Dibenzothiophene oxide compound, and process for producing the same

ABSTRACT

There are disclosed novel compounds, liquid crystal compositions, polymers, optically anisotropic products, and optical or liquid or liquid crystal elements that have large refractive index anisotropy, mix easily with other liquid crystals, have advantageous stability against light, and exhibit absorption at practically short wavelength in the ultraviolet region. The compounds are represented by the formula (1) and have a phenylacetylene structure, wherein difference ΔE in energy of HOMO of parts (1-1), (1-2) and (1-3) calculated by the method of molecular orbitals is not less than 0.3 electronvolt, and the polarizability anisotropy Δα of a molecule represented by the formula (1) calculated in the same way is not lower than 500 A.U.: 
     
       
         
         
             
             
         
       
     
     (A 1  to A 4 : H, F, alkyl or alkoxy group of C1 to C10 optionally substituted with F; P 1 , P 2 ; structure fulfilling the conditions of HOMO energy and polarizability).

FIELD OF ART

The present invention relates to novel compounds having aphenylacetylene structure, that are useful as optical, display, andrecording materials, as optical compensators, polarizer materials,reflector plates, scattering plates, brightness enhancement films, andfilms having coloring effect, all for liquid crystal devices, and as acomponent of liquid crystal materials for liquid crystal displayelements. The present invention also relates to liquid crystalcompositions, polymers, optically anisotropic products, optical orliquid crystal elements, novel dibenzothiophene compounds that may beused for production of the compounds having a phenylacetylene structure,intermediates thereof, and process for producing the same.

BACKGROUND ART

Improvement in performance of liquid crystal display elements has becomean essential issue with the recent development in information-orientedsociety. For higher processing speed and performance, liquid crystalcompositions must contain a component having large refractive indexanisotropy.

Tolan compounds are known as liquid crystal having relatively largerefractive index anisotropy (Mol. Cryst. Liq. Cryst., Vol. 23, p 233(1973)). However, the refractive index anisotropy of this compound isabout 0.2, which is not yet large enough.

There have also been developed compounds represented by the followingformulae and disclosed in JP-2-83340-A and JP-9-216841-A:

(wherein “Alkyl” stands for an alkyl group)

(wherein R stands for an alkyl group; Y stands for R, a fluorine,chlorine, bromine, or iodine atom, or a cyano group; H¹ to H¹² eachstands for a hydrogen, fluorine, or chlorine atom, provided that atleast one of H¹ to H¹² stands for a fluorine or chlorine atom).

The refractive index anisotropy of these compounds is larger than thatof the tolan compounds, but is yet as small as about 0.4. In the secondcompound, when the hydrogen atoms are substituted with halogen atomssuch as fluorine atoms for improved compatibility, the refractive indexanisotropy becomes still smaller, e.g. about 0.3. Under suchcircumstances, development of liquid crystalline compounds with largerrefractive index anisotropy is demanded.

However, if the improvement in refractive index anisotropy is sought byextending the conjugated pi-electron systems in such compounds, peaks ofthe absorption spectrum of the compounds in the ultraviolet and visibleregions shift to the longer wavelength side, sometimes resulting inundesirable coloring of the compound.

There have been discussed possible application of liquid crystallinematerials not only to a switching element of displays for switching thedisplay modes such as TN or STN mode, but also to retarders, polarizers,polarizing prisms, beam splitters, reflectors, holographic elements,color separators, or various optical filters, which make use of theoptical anisotropy of the materials such as alignment and refractiveindex. Improvement in performance of display elements has also become anessential issue with the recent development of the information-orientedsociety.

As techniques for production of optically anisotropic products from suchliquid crystalline materials, there are known, for example, methods ofphotopolymerizing a liquid crystalline compound having a polymerizablefunctional group, or a polymerizable liquid crystal compositioncontaining such a compound, by irradiating the compound or thecomposition in a liquid crystal state with ultraviolet or visibleirradiation. These methods intend, in other words, to produce polymerswherein the liquid crystal molecules aligned in the liquid crystal stateare semipermanently fixed for achieving stable optical functions.

Recently known liquid crystalline compounds having a polymerizablefunctional group are disclosed in JP-A-11-116534 and JP-A-11-80090, theformer proposing mainly a compound having a phenylbenzoate core, and thelatter a compound having a core including phenylbenzoate,cyclohexylphenyl, and tolan. Neither of the compounds, however, has acore exhibiting particularly large refractive index anisotropy (Δn).

It is known that a substituent may be introduced into a dibenzothiophenecompound through a process disclosed in J. Am. Chem. Soc., 1948, 70,1748, or in Heterocyclic Chem., 1985, 22, 215. However, by theseprocesses, it is hard to introduce two highly reactive substituentsselectively into the 3- and 7-positions of a dibenzothiophene compound.

DISCLOSURE OF THE INVENTION

It is therefore an object of the present invention to provide novelcompounds having a phenylacetylene structure that have large refractiveindex anisotropy, mix easily with other liquid crystals, haveadvantageous stability against light, and exhibit absorption atwavelength in the ultraviolet region that is short enough for practicaluse.

It is another object of the present invention to provide, utilizing theabove-mentioned novel compounds having a phenylacetylene structure,polymers, liquid crystal compositions, optically anisotropic products,and optical or liquid crystal elements, which are useful inmanufacturing optical compensators for liquid crystal devices, polarizermaterials, reflectors, scattering plates, and films having coloringeffect.

It is still another object of the present invention to provide noveldibenzothiophene compounds having two reactive substituents at 3- and7-positions, which are useful as optically functional materials, andalso useful, for example, in manufacture of the novel compounds having aphenylacetylene structure, as well as to provide intermediates of thedibenzothiophene compounds, and methods for highly selectively producingsuch compounds or intermediates.

The present inventors have made intensive studies for achieving theabove objects to find that a certain kind of phenylacetylene compoundshas sufficiently large refractive index anisotropy, exhibits absorptionat practically short wavelength in the ultraviolet region of theabsorption spectrum, and thus achieve the above objects, therebycompleting the present invention.

According to the present invention, there is provided a compoundrepresented by the formula (1) having a phenylacetylene structure,

wherein difference ΔE in energy of the highest occupied molecularorbital (HOMO) of parts in the formula (1) each represented by theformula (1-1), (1-2), or (1-3) calculated by method of molecularorbitals satisfies the following formula:

ΔE=E ₁₋₁−(E ₁₋₂ +E ₁₋₃)/2≧0.3 electronvolt

wherein E₁₋₁, E₁₋₂, and E₁₋₃ denote the HOMO energy of correspondingparts represented by the formulae (1-1), (1-2), and (1-3), respectively,of the formula (1) calculated by the method of molecular orbitals, and

wherein polarizability anisotropy Δα of a molecule represented by theformula (1) calculated by said method is not lower than 500 atomicunits:

wherein A¹ to A⁴ each independently stands for a hydrogen atom, afluorine atom, or an alkyl or alkoxy group having 1 to 10 carbon atomsoptionally substituted with at least one fluorine atom; and P¹ and P²may have any chemical structures as long as P¹ and P² satisfy saidconditions of the HOMO energy and polarizability anisotropy.

According to the present invention, there is also provided a compoundrepresented by the formula (2) having a phenylacetylene structure:

wherein A⁹ to A¹² each independently stands for a hydrogen atom, afluorine atom, or an alkyl or alkoxy group having 1 to 10 carbon atomsoptionally substituted with at least one fluorine atom; P³ and P⁴ eachstands for the formula (2-1) or (2-2), with at least one of P³ and P⁴standing for the formula (2-1):

wherein A³⁷ to A⁴² in the formula (2-1) and A⁵ to A⁸ in the formula(2-2) each independently stands for a hydrogen atom, a fluorine atom, oran alkyl or alkoxy group having 1 to 10 carbon atoms optionallysubstituted with at least one fluorine atom;R¹¹ and R¹² each independently stands for a hydrogen atom, a fluorineatom, a cyano group, —SF₅, —NCS, a 4-R²³-(cycloalkyl) group, a4-R²³-(cycloalkenyl) group, an R²⁴—(O)q group, or a group represented bythe formula (3), wherein R²³ stands for a hydrogen atom or a straight orbranched alkyl group having 1 to 12 carbon atoms optionally substitutedwith at least one fluorine atom, R²⁴ stands for a straight or branchedalkyl group having 1 to 12 carbon atoms optionally substituted with atleast one fluorine atom, or a strait or branched alkenyl or alkynylgroup having 3 to 12 carbon atoms optionally substituted with at leastone fluorine atom, q denotes 0 to 1,

wherein n denotes 0 to 1, and m denotes an integer of 1 to 20, B¹ standsfor a hydrogen atom or a methyl group, when both R¹¹ and R¹² stand for agroup represented by the formula (3), n, m, and B¹ in one group of theformula (3) may be the same as or different from those of the other.

According to the present invention, there is provided a liquid crystalcomposition comprising at least one compound represented by the formula(1) or (2).

According to the present invention, there is also provided a polymerobtained by polymerization of at least one compound represented by theformula (1) wherein at least one of P¹ and P² has an acrylate ormethacrylate group on its terminal, or by polymerization of at least onecompound represented by the formula (2) wherein at least one of R¹¹ andR¹² stands for a group represented by the formula (3).

According to the present invention, there is further provided a polymerobtained by polymerization of the liquid crystal composition mentionedabove.

According to the present invention, there is further provided a liquidcrystal composition comprising:

at least one material selected from the group consisting of theabove-mentioned compounds and the above-mentioned polymers, and

at least one monomer other than the above-mentioned compounds selectedfrom the group consisting of methacrylate esters, acrylate esters,epoxy, and vinyl ethers.

According to the present invention, there is also provided a polymerobtained by polymerization of this liquid crystal composition.

According to the present invention, there is also provided an opticallyanisotropic product produced with at least one material selected fromthe group consisting of the above-mentioned compounds, theabove-mentioned polymers, and the above-mentioned liquid crystalcompositions, as well as an optical or liquid crystal elementmanufactured with at least one of these materials.

According to the present invention, there is further provided adibenzothiophene compound represented by the formula (A-1):

wherein A¹ to A⁶ each independently stands for a hydrogen atom, afluorine atom, or an alkyl or alkoxy group having 1 to 10 carbon atomsoptionally substituted with at least one fluorine atom; X stands for ahalogen atom; and Y stands for a halogen atom or a hydroxyl group.

According to the present invention, there is also provided adibenzothiophene compound represented by the formula (A-2):

wherein A¹ to A⁶ and X mean the same as those in the formula (A-1).

According to the present invention, there is further provided adibenzothiophene oxide compound represented by the formula (A-3):

wherein A¹ to A⁶ and X mean the same as those in the formula (A-1).

According to the present invention, there is also provided adibenzothiophene oxide compound represented by the formula (A-4):

wherein A¹ to A⁶ and X mean the same as those in the formula (A-1).

According to the present invention, there is also provided a method forproducing a dibenzothiophene compound represented by the formula (A-1)comprising:

diazotizing a dibenzothiophene compound represented by the formula (A-2)to obtain a diazonium salt, and

decomposing said diazonium salt in the presence of an anioncorresponding to Y in the formula (A-1).

According to the present invention, there is also provided a method forproducing a dibenzothiophene compound represented by the formula (A-2)comprising reducing a dibenzothiophene oxide compound represented by theformula (A-3).

According to the present invention, there is also provided a method forproducing a dibenzothiophene oxide compound represented by the formula(A-3) comprising nitrating a dibenzothiophene oxide compound representedby the formula (A-4).

According to the present invention, there is also provided a method forproducing a dibenzothiophene oxide compound represented by the formula(A-4) comprising oxidizing a dibenzothiophene compound represented bythe formula (A-5):

wherein A¹ to A⁶ and X mean the same as those in the formula (A-1)

PREFERRED EMBODIMENTS OF THE INVENTION

The present invention will now be explained in detail.

The compounds having a phenylacetylene structure according to thepresent invention (referred to as compounds of the present inventionhereinbelow) are compounds represented by the formula (1) or (2)mentioned above. A¹ to A⁴ in the formula (1) and A⁹ to A¹² in theformula (2) each independently stands for a hydrogen atom, a fluorineatom, an alkyl or alkoxy group having 1 to 10 carbon atoms optionallysubstituted with at least one fluorine atom. It is preferred that atleast one of A¹ to A⁴ and at least one of A⁹ to A¹² stand for the alkylor alkoxy group optionally substituted with at least one fluorine atom.In the formula (2), when all of A⁹ to A¹² each stands for an alkylgroup, the number of carbon atoms in each group is preferably not lessthan two.

In the formula (1), P¹ and P² may have any chemical structures as longas P¹ and P² satisfy the conditions of the HOMO energy andpolarizability anisotropy mentioned above. Examples of the combinationof P¹ and P² may include the pairs of groups corresponding to P¹ and P²in the compounds to be specified later.

In the formula (2), P³ and P⁴ each stands for the formula (2-1) or(2-2), and at least one of P³ and P⁴ stands for the formula (2-1). R¹¹and R¹² each independently stands for a hydrogen atom, a fluorine atom,a cyano group, —SF₅, —NCS, 4-R²³-(cycloalkyl) group,4-R²³-(cycloalkenyl) group, R²⁴—(O)_(q) group, or a group represented bythe formula (3), wherein R²³ stands for a hydrogen atom, or a straightor branched alkyl group having 1 to 12 carbon atoms optionallysubstituted with at least one fluorine atom, R²⁴ stands for a straightor branched alkyl group having 1 to 12 carbon atoms optionallysubstituted with at least one fluorine atom, or a straight or branchedalkenyl or alkynyl group having 3 to 12 carbon atoms optionallysubstituted with at least one fluorine atom, and q denotes 0 or 1. Inthe formula (3), n denotes 0 or 1, and m denotes an integer of 1 to 20,B¹ stands for a hydrogen atom or a methyl group. When both R¹¹ and R¹²stand for a group represented by the formula (3), n, m, and B¹ in onegroup of the formula (3) may be the same as or different from those ofthe other. Alternatively, only one of R¹¹ and R¹² may stand for a grouprepresented by the formula (3).

The compound represented by the formula (1) is a compound whereindifference ΔE in energy of the highest occupied molecular orbital (HOMO)of the parts of the formula (1) each represented by the formula (I-1),(I-2) or (1-3) calculated by the method of molecular orbitals is notless than 0.3 electronvolt, preferably not less than 0.35 electronvolt,and the polarizability anisotropy Δα of a molecule represented by theformula (1) calculated by the same method is not lower than 500 atomicunits, preferably not lower than 600 atomic units.

The polarizability anisotropy Δα of a molecule is a value obtained bycalculation according to the following formula, denoting thepolarizability along a long axis of the molecule by αxx, and those alongthe axes perpendicular to this axis by αyy and αzz:

Δα=αxx−(αyy+αzz)/2

A long axis of a molecule may be taken in the direction in which themolecule has approximately the maximum length. In the formula (1), forexample, the axis connecting the terminal carbon in the carbon-carbontriple bond bonded to P¹ and the terminal carbon in the carbon-carbontriple bond bonded to P², may be the long axis of the moleculerepresented by the formula (1).

Examples of the compounds represented by the formulae (1) and (2) mayinclude compounds represented by the following formulae.

In the above formulae, R¹¹ and R¹² may stand for, for example, ahydrogen atom; a fluorine atom; an alkyl group such as a methyl, ethyl,propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, ordodecyl group, or an alkyl group substituted with at least one fluorineatom, i.e. a fluoroalkyl group such as a trifluoromethyl group; analkenyl group such as an ethenyl, propenyl, butenyl, pentenyl, hexenyl,heptenyl, octenyl, nonenyl, decenyl, undecenyl, or dodecenyl group, oran alkenyl group substituted with at least one fluorine atom, i.e. afluoroalkenyl group; an alkynyl group such as a propynyl, butynyl,pentynyl, hexynyl, heptynyl, octynyl, nonynyl, decynyl, or dodecynylgroup, or an alkynyl group substituted with at least one fluorine atom,i.e. a fluoroalkynyl group; an alkoxy group such as a methoxy, ethoxy,propoxy, butoxy, pentyloxy, hexyloxy, octyloxy, nonyloxy, decyloxy,undecyloxy, or dodecyloxy group, or an alkoxy group substituted with atleast one fluorine atom, i.e. a fluoroalkoxy group such as a methoxygroup having 1 to 3 substituted fluorine atoms, or an ethoxy grouphaving 1 to 5 substituted fluorine atoms; an alkenyloxy group such as avinyloxy, propenyloxy, butenyloxy, pentenyloxy, hexenyloxy, heptenyloxy,octenyloxy, nonenyloxy, or decenyloxy group, or an alkenyloxy groupsubstituted with at least one fluorine atom, i.e. a fluoroalkenyloxygroup; an alkynyloxy group such as a propionyloxy, butynyloxy,pentynyloxy, hexynyloxy, heptynyloxy, octynyloxy, nonynyloxy,decynyloxy, undecynyloxy, or dodecynyloxy group, or an alkynyloxy groupsubstituted with at least one fluorine atom, i.e. a fluoroalkynyloxygroup; an alkoxyalkyl group such as a methoxymethyl, ethoxymethyl,propoxymethyl, butoxymethyl, pentyloxymethyl, hexyloxymethyl,heptyloxymethyl, octyloxymethyl, nonyloxymethyl, decyloxymethyl,methoxyethyl, ethoxyethyl, propoxyethyl, butoxyethyl, pentyloxyethyl,hexyloxyethyl, heptyloxyethyl, octyloxyethyl, nonyloxyethyl,decyloxyethyl, methoxypropyl, ethoxypropyl, propoxypropyl, butoxypropyl,pentyloxypropyl, hexyloxypropyl, heptyloxypropyl, octyloxypropyl,nonyloxypropyl, methoxybutyl, ethoxybutyl, propoxybutyl, butoxybutyl,pentyloxybutyl, hexyloxybutyl, heptyloxybutyl, octyloxybutyl,methoxypentyl, ethoxypentyl, propoxypentyl, butoxypentyl,pentyloxypentyl, hexyloxypentyl, or heptyloxypentyl group, or analkoxyalkyl group substituted with at least one fluorine atom, i.e., afluoroalkoxyalkyl group; a branched alkyl group such as a2-methylpropyl, 2-methylbutyl, 3-methylbutyl, or 3-methylpentyl group,or a branched alkyl group substituted with at least one fluorine atom,i.e., a branched fluoroalkyl group; a branched alkyloxy group such as a2-methylpropyloxy, 2-methylbutyloxy, 3-methylbutyloxy, or3-methylpentyloxy group, or a branched alkyloxy group substituted withat least one fluorine atom, i.e., a branched fluoroalkyloxy group; a4-alkylcycloalkyl group such as a 4-methylcyclohexyl, 4-ethylcyclohexyl,4-propylcyclohexyl, 4-butylcyclohexyl, 4-pentylcyclohexyl,4-hexylcyclohexyl, 4-heptylcyclohexyl, 4-octylcyclohexyl,4-nonylcyclohexyl, or 4-decylcyclohexyl group, or a 4-alkylcycloalkylgroup substituted with at least one fluorine atom, i.e., a4-fluoroalkylcycloalkyl group; a 4-alkylcycloalkenyl group such as a4-propylcyclohexenyl or 4-pentylcyclohexenyl group, or a4-alkylcycloalkenyl group substituted with at least one fluorine atom,i.e., a 4-fluoroalkylcycloalkenyl group; a cyano group; —SF₅; —NCS;—OCH₂OCOCHCH₂, —OC₂H₄OCOCHCH₂, —OC₃H₆OCOCHCH₂, —OC₄H₈OCOCHCH₂,—OC₅H₁₀OCOCHCH₂, —OC₆H₁₂OCOCHCH₂, —OC₇H₁₄OCOCHCH₂, —OC₈H₁₆OCOCHCH₂,—OC₉H₁₈OCOCHCH₂, —OC₁₀H₂₀OCOCHCH₂; —OCH₂OCOC(CH₃)CH₂,—OC₂H₄OCOC(CH₃)CH₂, —OC₃H₆OCOC(CH₃)CH₂, —OC₄H₁₀OCOC(CH₃)CH₂,—OC₅H₁₀OCOC(CH₃)CH₂, —OC₆H₁₂OCOC(CH₃)CH₂, —OC₇H₁₄OCOC(CH₃)CH₂,—OC₈H₁₆OCOC(CH₃)CH₂, —OC₉H₁₈OCOC(CH₃)CH₂, or —OC₁₀H₂₀OCOC(CH₃)CH₂.However, R¹¹ and R¹² may not be limited to these examples.

The compounds of the present invention may be synthesized throughordinary organic synthesizing processes. For example, a phenylacetylenecompound wherein three aryl groups are bonded together via two acetylenegroups therebetween, may be synthesized by suitably combiningSonogashira reaction (Organo Copper Reagents. A Practical Approach;Taylor, R. J. K. Ed.; Oxford University Press: Oxford, 1994; Chapter 10,pp 217-236. Metal-Catalyzed Cross-Coupling Reactions; Diederich, F.,Stang, P. J. Eds; Wiley: Weinheim, 1997; Chapter 5, pp 203-229), usingsuitable starting materials, such as by palladium-catalyzed couplingreaction of an aromatic halide or a sulfonate of aromatic alcohol suchas trifluoromethanesulfonate with the methine part of an acetyleneterminal of an acetylene compound in the presence of a base.

The liquid crystal composition of the present invention contains atleast one compound of the present invention as a component. Othercomponents of the composition are not particularly limited, but arepreferably compounds or compositions exhibiting a liquid crystal phase.

Such other components of the liquid crystal composition of the presentinvention may include, for example, at least one liquid crystallinecompound represented by any of the formulae (4) to (7). These liquidcrystalline compounds may be synthesized through ordinary organicsynthesizing processes.

In the formula (4), A²⁵ to A³⁶ each independently stands for a hydrogenatom, a fluorine atom, an alkyl or alkoxy group having 1 to 10 carbonatoms optionally substituted with at least one fluorine atom. B⁴¹ andB⁴² each stands for a hydrogen atom or a methyl group. p⁴, q⁴, r⁴, s⁴,and t⁴ each denotes 0 or 1, provided that when q⁴ is 0, at least one ofA²⁹ to A³⁶ stands for an alkyl or alkoxy group having 1 to 10 carbonatoms optionally substituted with at least one fluorine atom. m⁴¹ andn⁴¹ each denotes an integer of 0 to 14, provided that when s⁴ is 1, n⁴¹is not 0, and that when t⁴ is 1, m⁴¹ is not 0. W⁴¹ stands for a singlebond, —CH₂CH₂—, or —C≡C—.

Examples of the compound represented by the formula (4) may include thecompounds represented by the following formulae:

In the formula (5), A¹³ to A²⁴ each independently stands for a hydrogenatom, a fluorine atom, an alkyl or alkoxy group having 1 to 10 carbonatoms optionally substituted with at least one fluorine atom, and atleast one of A¹³ to A²⁴ stands for an alkyl or alkoxy group having 1 to10 carbon atoms optionally substituted with at least one fluorine atom.R³¹ and R³² each independently stands for a hydrogen atom, a fluorineatom, a cyano group, —SF₅, —NCS, 4-R³³-(cycloalkyl) group,4-R³³—(cycloalkenyl) group, or R³⁴—(O)_(q31) group, wherein R³³ standsfor a hydrogen atom or a straight or branched alkyl group having 1 to 12carbon atoms optionally substituted with at least one fluorine atom, R³⁴stands for a straight or branched alkyl group having 1 to 12 carbonatoms optionally substituted with at least one fluorine atom, and q³¹denotes 0 or 1.

Examples of the compound represented by the formula (5) may include thecompounds represented by the following formulae:

In the above formulae, R¹ and R² correspond to R³¹ and R³² in theformula (5), respectively, and may each stands for, for example, ahydrogen atom; a fluorine atom; an alkyl group such as a methyl, ethyl,propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, ordodecyl group, or an alkyl group substituted with at least one fluorineatom, i.e. a fluoroalkyl group such as a trifluoromethyl group; analkoxy group such as a methoxy, ethoxy, propoxy, butoxy, pentyloxy,hexyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, or dodecyloxy group,or an alkoxy group substituted with at least one fluorine atom, i.e. afluoroalkoxy group such as a methoxy group having 1 to 3 substitutedfluorine atoms, or an ethoxy group having 1 to 5 substituted fluorineatoms; an alkoxyalkyl group such as a methoxymethyl, ethoxymethyl,propoxymethyl, butoxymethyl, pentyloxymethyl, hexyloxymethyl,heptyloxymethyl, octyloxymethyl, nonyloxymethyl, decyloxymethyl,methoxyethyl, ethoxyethyl, propoxyethyl, butoxyethyl, pentyloxyethyl,hexyloxyethyl, heptyloxyethyl, octyloxyethyl, nonyloxyethyl,decyloxyethyl, methoxypropyl, ethoxypropyl, propoxypropyl, butoxypropyl,pentyloxypropyl, hexyloxypropyl, heptyloxypropyl, octyloxypropyl,nonyloxypropyl, methoxybutyl, ethoxybutyl, propoxybutyl, butoxybutyl,pentyloxybutyl, hexyloxybutyl, heptyloxybutyl, octyloxybutyl,methoxypentyl, ethoxypentyl, propoxypentyl, butoxypentyl,pentyloxypentyl, hexyloxypentyl, or heptyloxypentyl group, or analkoxyalkyl group substituted with at least one fluorine atom, i.e., afluoroalkoxyalkyl group; a branched alkyl group such as a2-methylpropyl, 2-methylbutyl, 3-methylbutyl, or 3-methylpentyl group,or a branched alkyl group substituted with at least one fluorine atom,i.e., a branched fluoroalkyl group; a branched alkyloxy group such as a2-methylpropyloxy, 2-methylbutyloxy, 3-methylbutyloxy, or3-methylpentyloxy group, or a branched alkyloxy group substituted withat least one fluorine atom, i.e., a branched fluoroalkyloxy group; a4-alkylcycloalkyl group such as a 4-methylcyclohexyl, 4-ethylcyclohexyl,4-propylcyclohexyl, 4-butylcyclohexyl, 4-pentylcyclohexyl,4-hexylcyclohexyl, 4-heptylcyclohexyl, 4-octylcyclohexyl,4-nonylcyclohexyl, or 4-decylcyclohexyl group, or a 4-alkylcycloalkylgroup substituted with at least one fluorine atom, i.e., a4-fluoroalkylcycloalkyl group; a 4-alkylcycloalkenyl group such as a4-propylcyclohexenyl or 4-pentylcyclohexenyl group, or a4-alkylcycloalkenyl group substituted with at least one fluorine atom,i.e., a 4-fluoroalkylcycloalkenyl group; a cyano group; —SF₅; or —NCS.

In the formula (6), A²⁵ to A³⁶ each independently stands for a hydrogenatom, a fluorine atom, or an alkyl group having 1 to 10 carbon atoms. mdenotes 0 or 1. R⁴¹ stands for a hydrogen atom or a straight or branchedalkyl group having 1 to 12 carbon atoms optionally substituted with atleast one fluorine atom. R⁴² stands for R⁴¹, a fluorine atom, a cyanogroup, 4-R⁴³—(cycloalkyl) group, 4-R⁴³-(cycloalkenyl) group, orR⁴⁴—(O)_(q41) group, wherein R⁴³ stands for a hydrogen atom or astraight or branched alkyl group having 1 to 12 carbon atoms optionallysubstituted with at least one fluorine atom, R⁴⁴ stands for a straightor branched alkyl group having 1 to 12 carbon atoms optionallysubstituted with at least one fluorine atom, and q⁴¹ denotes 0 or 1.

Examples of the compound represented by the formula (6) may include thecompounds represented by the following formulae:

In the above formulae, R¹ and R² correspond to R⁴¹ and R⁴² in theformula (6), respectively, and may be the same as those listed asexamples of R¹ and R² corresponding to R³¹ and R³² in the formula (5),except for —SF₅ and —NCS, but are not limited to these.

In the formula (7), Rings A, B, C, and D each independently stands for1,4-phenylene, 1,4-cyclohexylene, 1,4-cyclohexenylene,4,1-cyclohexenylene, 2,5-cyclohexenylene, 5,2-cyclohexenylene,3,6-cyclohexenylene, 6,3-cyclohexenylene, 2,5-pyrimidinediyl,5,2-pyrimidinediyl, 2,5-pyridinediyl, 5,2-pyridinediyl, 2,5-dioxanediyl,or 5,2-dioxanediyl, with at least one of the hydrogen atoms on Rings A,B, C, and D being optionally substituted with a fluorine atom. R⁵¹ andR⁵² each independently stands for a hydrogen atom, a fluorine atom, afluoromethyl group, a difluoromethyl group, a trifluoromethyl group, afluoromethoxy group, a difluoromethoxy group, a trifluoromethoxy group,a cyano group, an alkyl group having 1 to 12 carbon atoms, an alkenylgroup having 3 to 12 carbon atoms, an alkynyl group having 3 to 12carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyloxygroup having 3 to 12 carbon atoms, an alkynyloxy group having 3 to 12carbon atoms, an alkoxyalkyl group having 2 to 16 carbon atoms, analkoxyalkenyl group having 3 to 16 carbon atoms, or a group representedby the formula (7-1), (7-2), or (7-3). In the formulae (7-1) to (7-3),m⁷ denotes an integer of 1 to 12, and n⁷ denotes 0 or 1. These alkyl,alkenyl, and alkynyl groups may optionally have at least one methylenegroup substituted with an oxygen, sulfur, or silicon atom, and mayeither be straight or branched. Z¹, Z², and Z³ each independently standsfor —COO—, —OCO—, —OCH₂—, —CH₂O—, an alkylene group having 1 to 5 carbonatoms, an alkenylene group having 2 to 5 carbon atoms, an alkynylenegroup having 2 to 5 carbon atoms, or a single bond. b, c, and d eachindependently denotes 0 or 1, with b+c+d≧1.

Examples of the compound represented by the formula (7) may include thecompounds represented by the following formulae:

In the above formulae showing the examples of the compound representedby the formula (7), R⁵ and R⁶ correspond to R⁵¹ and R⁵² in the formula(7), respectively.

Examples of R⁵ may include a hydrogen atom; or a methyl, ethyl, propyl,butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl,ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl,nonenyl, decenyl, undecenyl, dodecenyl, methoxy, ethoxy, propoxy,butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy,undecyloxy, dodecyloxy, vinyloxy, propenyloxy, butenyloxy, pentenyloxy,hexenyloxy, heptenyloxy, octenyloxy, nonenyloxy, decenyloxy,propynyloxy, butynyloxy, pentynyloxy, hexynyloxy, heptynyloxy,octynyloxy, nonynyloxy, decynyloxy, undecynyloxy, dodecynyloxy,methoxymethyl, ethoxymethyl, propoxymethyl, butoxymethyl,pentyloxymethyl, hexyloxymethyl, heptyloxymethyl, octyloxymethyl,nonyloxymethyl, decyloxymethyl, methoxyethyl, ethoxyethyl, propoxyethyl,butoxyethyl, pentyloxyethyl, hexyloxyethyl, heptyloxyethyl,octyloxyethyl, nonyloxyethyl, decyloxyethyl, methoxypropyl,ethoxypropyl, propoxypropyl, butoxypropyl, pentyloxypropyl,hexyloxypropyl, heptyloxypropyl, octyloxypropyl, nonyloxypropyl,decyloxypropyl, methoxybutyl, ethoxybutyl, propoxybutyl, butoxybutyl,pentyloxybutyl, hexyloxybutyl, heptyloxybutyl, octyloxybutyl,nonyloxybutyl, decyloxybutyl, methoxypentyl, ethoxypentyl,propoxypentyl, butoxypentyl, pentyloxypentyl, hexyloxypentyl,heptyloxypentyl octyloxypentyl, nonyloxypentyl, or decyloxypentyl groupoptionally substituted with at least one fluorine atom. However, R⁵ isnot limited to the above examples.

Examples of R⁶ may include a hydrogen atom; a fluorine atom; afluoromethyl, difluoromethyl, trifluoromethyl, fluoromethoxy,difluoromethoxy, trifluoromethoxy, or cyano group; a methyl, ethyl,propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl,dodecyl, ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl,octenyl, nonenyl, decenyl, undecenyl, dodecenyl, methoxy, ethoxy,propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy,decyloxy, undecyloxy, dodecyloxy, vinyloxy, propenyloxy, butenyloxy,pentenyloxy, hexenyloxy, heptenyloxy, octenyloxy, nonenyloxy,decenyloxy, propynyloxy, butynyloxy, pentynyloxy, hexynyloxy,heptynyloxy, octynyloxy, nonynyloxy, decynyloxy, undecynyloxy,dodecynyloxy, methoxymethyl, ethoxymethyl, propoxymethyl, butoxymethyl,pentyloxymethyl, hexyloxymethyl, heptyloxymethyl, octyloxymethyl,nonyloxymethyl, decyloxymethyl, methoxyethyl, ethoxyethyl, propoxyethyl,butoxyethyl, pentyloxyethyl, hexyloxyethyl, heptyloxyethyl,octyloxyethyl, nonyloxyethyl, decyloxyethyl, methoxypropyl,ethoxypropyl, propoxypropyl, butoxypropyl, pentyloxypropyl,hexyloxypropyl, heptyloxypropyl, octyloxypropyl, nonyloxypropyl,decyloxypropyl, methoxybutyl, ethoxybutyl, propoxybutyl, butoxybutyl,pentyloxybutyl, hexyloxybutyl, heptyloxybutyl, octyloxybutyl,nonyloxybutyl, decyloxybutyl, methoxypentyl, ethoxypentyl,propoxypentyl, butoxypentyl, pentyloxypentyl, hexyloxypentyl,heptyloxypentyl octyloxypentyl, nonyloxypentyl, or decyloxypentyl groupoptionally substituted with at least one fluorine atom; —OCH₂OCOCHCH₂,—OC₂H₄OCOCHCH₂, —OC₃H₆OCOCHCH₂, —OCH₈OCOCHCH₂, —OC₅H₁₀OCOCHCH₂,—OC₆H₁₂OCOCHCH₂, —OC₇H₁₄OCOCHCH₂, —OC₈H₁₆OCOCHCH₂, —OC₉H₁₈OCOCHCH₂,—OC₁₀H₂₀OCOCHCH₂; —OCH₂OCOC(CH₃)CH₂, —OC₂H₄OCOC(CH₃)CH₂,—OC₃H₆OCOC(CH₃)CH₂, —OC₄H₈OCOC(CH₃)CH₂, —OC₅H₁₀OCOC(CH₃)CH₂,—OCH₁₂OCOC(CH₃)CH₂—OC₇H₁₄OCOC(CH₃)CH₂, —OC₈H₁₆OCOC(CH₃)CH₂,—OC₉H₁₈OCOC(CH₃)CH₂, —OC₁₀H₂₀OCOC(CH₃)CH₂; —OCH₂CHCH₂, —OC₂H₄CHCH₂,—OC₃H₆CHCH₂, —OC₄H₈CHCH₂, —OC₅H₁₀CHCH₂, —OC₆H₁₂CHCH₂, —OC₇H₁₄CHCH₂,—OC₈H₁₆CHCH₂, —OC₉H₁₈CHCH₂, or —OC₁₀H₂₀CHCH₂. However, R⁶ is not limitedto these examples.

In the above formulae showing the examples of the compound representedby the formula (7), W stands for a hydrogen or fluorine atom, x denotesan integer of 0 to 3, Ring H stands for 1,4-cyclohexylene, and Ring Gstands for 1,4-phenylene, 1,4-cyclohexylene, 1,4-cyclohexenylene,4,1-cyclohexenylene, 2,5-cyclohexenylene, 5,2-cyclohexenylene,3,6-cyclohexenylene, 6,3-cyclohexenylene, 2,5-pyrimidinediyl,5,2-pyrimidinediyl, 2,5-pyridinediyl, 5,2-pyridinediyl, 2,5-dioxanediyl,or 5,2-dioxanediyl, optionally substituted with at least one fluorineatom. Among these, Ring G is preferably 1,4-cyclohexylene,1,4-cyclohexenylene, 4,1-cyclohexenylene, 2,5-cyclohexenylene,5,2-cyclohexenylene, 3,6-cyclohexenylene, or 6,3-cyclohexenylene.

In the liquid crystal composition of the present invention, a preferablecontent of the compound represented by the formula (1) or (2) is 1 to99.9% by weight, preferably 5 to 99% by weight of the liquid crystalcomposition. The content of the compound represented by any of theformulae (4) to (7), if contained in the composition, may suitably beselected depending on the use of the composition. Further, a compoundwithout a photopolymerizable functional group may also be contained, ofwhich content may suitably be decided depending on the use of thecomposition, as long as the liquid crystallinity of the composition isnot impaired. However, if a temperature-dependent change in therefractive index anisotropy of the composition is undesirable, thecontent of the compound without a photopolymerizable functional group ispreferably be in the range of 0 to 50% by weight.

The liquid crystal composition of the present invention may contain achiral compound for the purpose of producing a twisted oriented polymer.The chiral compound per se does not have to exhibit liquidcrystallinity, nor does it have to have a polymerizable functionalgroup. The chiral compound is not particularly limited, and may beselected from the following compounds. In the following formulae, theasterisk (*) indicates an asymmetric carbon. The content of the chiralcompound in the composition may suitably be selected depending on theuse of the liquid crystal composition, and not particularly limited.

The liquid crystal composition of the present invention may contain acompound that has at least one photopolymerizable functional group anddoes not exhibit liquid crystallinity. Any such compounds may be used aslong as the compounds are recognized in the art as polymerizablemonomers or oligomers, and acrylate compounds, methacrylate compounds,and vinyl ether compounds are particularly preferred.

The liquid crystal composition of the present invention may furthercontain a thermal polymerization initiator or a photopolymerizationinitiator for the purpose of improving the polymerizability. Examples ofthe thermal polymerization initiator may include benzoyl peroxide andazobis(butyronitrile), and examples of the photopolymerization initiatormay include benzoin ethers, benzophenones, acetophenones, andbenzylketals. The amount of the polymerization initiator is preferablynot more than 10% by weight, more preferably 0.5 to 1.5% by weight ofthe liquid crystal composition.

When the liquid crystal composition of the present invention is to beused for preparing, for example, polarizing films, printing inks, orpaints, the composition may optionally contain pigments, coloringagents, or dyes depending on the use of the composition.

The liquid crystal composition of the present invention may contain atleast one compound selected from the group consisting of the compoundsof the present invention and polymers including homopolymers andcopolymers of the present invention to be discussed later, and at leastone monomer compound other than the compounds of the present inventionselected from the group consisting of methacrylate esters, acrylateesters, epoxy, and vinyl ethers. Such liquid crystal composition of thepresent invention may further contain, for example, optional componentsthat may be added as desired, such as the liquid crystalline compoundsrepresented by the formulae (4) to (7).

The monomer compound mentioned above may be any compound usuallyrecognized in the art as a polymerizable monomer, such as methacrylateesters, acrylate esters, epoxy, or vinyl ethers, but is not limited tothese examples.

The content of each component of the liquid crystal composition of thepresent invention may suitably be selected depending on the use of thecomposition. It is preferred that the content of the at least onecompound selected from the group consisting of the compounds andpolymers of the present invention is 1 to 99% by weight, and the contentof the monomer compound is 1 to 70% by weight.

The polymers of the present invention, including homopolymers andcopolymers, are not particularly limited in molecular weight and thelike properties, as long as they are polymers of one or more compoundsrepresented by the formula (1), in particular polymers of one or morecompounds represented by the formula (1) wherein at least one of P¹ andP² has an acrylate or methacrylate group on its terminal, polymers ofone or more compounds represented by the formula (2), in particularpolymers of one or more compounds represented by the formula (2) whereinat least one of R¹¹ and R¹² stands for a group represented by theformula (3), or polymers obtained by polymerization of the liquidcrystal compositions mentioned above.

The polymers of the present invention may preferably be produced, forexample, by photopolymerization by irradiation with energy beams such asultraviolet rays or electron beams. A light source for effecting suchphotopolymerization may be those emitting either polarized orunpolarized light. When a polymerization initiator that absorbs light inthe visible region is added to the liquid crystal material to bepolymerized, irradiation may be performed with visible light. In thiscase, two laser beams may be caused to interfere with the visible lightto thereby give spatially distributed intensity to the light beams. Theirradiation temperature is preferably in the range for allowingmaintenance of the liquid crystal state. When an optically anisotropicproduct is to be produced by photopolymerization, it is particularlypreferred to effect the polymerization at a temperature as close to theroom temperature as possible in order to avoid induction of unintendedthermal polymerization.

The obtained polymers may further be subjected to a heat treatment forinhibition of initial change and steady maintenance of theircharacteristics. The heat treatment may preferably be carried out atapproximately 50 to 200° C. for 30 seconds to 12 hours.

The optically anisotropic products of the present invention are notparticularly limited as long as they have been produced using at leastone material selected from the group consisting of the compounds,polymers, and liquid crystal compositions of the present invention. Theoptically anisotropic products may be prepared, for example, bypolymerizing a liquid crystalline polymerizable component such as acompound or liquid crystal composition of the present invention, withliquid crystal molecules being aligned. More specifically, the productsmay be produced by polymerizing the polymerizable component carried on asubstrate or held between substrates. The substrates used here may havebeen rubbed with a cloth on its surface, may have been provided with anorganic thin film, for example, of polyimide formed on its surface, andrubbed with a cloth, or may have been provided with an alignment layerformed by obliquely evaporating SiO₂. It is convenient and preferred touse a substrate with an organic thin film formed thereon that has beenrubbed with a cloth.

The substrate may be made of either an organic or inorganic material.Examples of the organic material may include polycarbonate, polyethyleneterephthalate, polystyrene, polyvinyl chloride, polyalylate, triacetylcellulose, and polysulfone. Examples of the inorganic material mayinclude glass and silicone.

When the alignment of the liquid crystal molecules is controlled by anelectric field, a substrate having an electrode layer may be used, onwhich layer the polyimide thin film is preferably formed. For alignmentof the liquid crystal molecules, photo-alignment technique may also beused instead of the rubbing method. Alternatively, it is also possibleto align the liquid crystal molecules by drawing following thepolymerization of the material.

The optically anisotropic product may be produced by polymerization,preferably photopolymerization by irradiation with energy beams such asultraviolet rays or electron beams. Alight source for thephotopolymerization may be a source of either polarized or unpolarizedlight. The temperature of the irradiation may be decided depending onthe use of the product; it is sometimes preferred to effect thepolymerization in a temperature range wherein the polymerizablecomponents are maintained in the liquid crystal state, and in some othertimes in a temperature range wherein the polymerization components arein the isotropic phase.

The optically anisotropic products thus produced may be used as they arewith the substrate, or only the polymer layer may be peeled off for useas an optically anisotropic product.

The optical or liquid crystal elements of the present invention are notparticularly limited as long as they have been produced using at leastone material selected from the group consisting of the compounds,polymers, and liquid crystal compositions of the present invention.Examples of the elements may include an element with a pair of electrodesubstrates holding at least one of the above materials therebetween, andan element having a structure similar to that of a conventional liquidcrystal display device. The electrodes used for fabricating the opticalor liquid crystal elements are not particularly limited in kind andshape, and any publicly known electrodes may be used. The optical orliquid crystal elements may be produced in accordance with a process forfabricating conventional elements, and other components may optionallybe added as desired.

Dibenzothiophene compound (A-1) represented by the formula (A-1) aboveaccording to the present invention may be used for producing thecompounds of the present invention or other liquid crystal materials.Dibenzothiophene compound (A-2) represented by the formula (A-2) aboveaccording to the present invention may be used for producing thedibenzothiophene compound (A-1). Dibenzothiophene oxide compound (A-3)represented by the formula (A-3) above according to the presentinvention may be used for producing the dibenzothiophene compound (A-2).Dibenzothiophene oxide compound (A-4) represented by the formula (A-4)according to the present invention may be used for producing thedibenzothiophene oxide compound (A-3). The dibenzothiophene oxidecompound (A-4) may be prepared by oxidizing a dibenzothiophene compound(A-5) represented by the formula (A-5).

In the formulae (A-1) to (A-5), A¹ to A⁶ each independently stands for ahydrogen atom, a fluorine atom, or an alkyl or alkoxy group having 1 to10 carbon atoms optionally substituted with at least one fluorine atom,X stands for a halogen atom, and Y stands for a halogen atom or ahydroxyl group.

Examples of each of A¹ to A⁶ may include a hydrogen atom; a fluorineatom; an alkyl group such as a methyl, ethyl, propyl, butyl, pentyl,hexyl, heptyl, octyl, nonyl, decyl, undecyl, or dodecyl group, or analkyl group substituted with at least one fluorine atom, i.e. afluoroalkyl group such as a trifluoromethyl or pentafluoroethyl group;or an alkoxy group such as a methoxy, ethoxy, propoxy, butoxy,pentyloxy, hexyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, ordodecyloxy group, or an alkoxy group substituted with at least onefluorine atom, i.e. a fluoroalkoxy group such as a methoxy group having1 to 3 substituted fluorine atoms, or an ethoxy group having 1 to 5substituted fluorine atoms.

Examples of the dibenzothiophene compound (A-1) of the present inventionmay include 7-chlorodibenzothiophene-3-ol, 7-bromodibenzothiophene-3-ol,7-iododibenzothiophene-3-ol, 3,7-dichlorodibenzothiophene,3-bromo-7-chlorodibenzothiophene, 3-chloro-7-iododibenzothiophene,3,7-dibromodibenzothiophene, 3-bromo-7-iododibenzothiophene,3,7-diiododibenzothiophene, 7-chloro-2-methyldibenzothiophene-3-ol,7-bromo-2-methyldibenzothiophene-3-ol,7-iodo-2-methyldibenzothiophene-3-ol,3,7-dichloro-2-methyldibenzothiophene,3-bromo-7-chloro-2-methyldibenzothiophene,3-chloro-7-iodo-2-methyldibenzothiophene,3,7-dibromo-2-methyldibenzothiophene,3-bromo-7-iodo-2-methyldibenzothiophene,3,7-diiodo-2-methyldibenzothiophene,7-chloro-8-methyldibenzothiophene-3-ol,7-bromo-8-methyldibenzothiophene-3-ol,7-iodo-8-methyldibenzothiophene-3-ol,3,7-dichloro-8-methyldibenzothiophene,3-bromo-7-chloro-8-methyldibenzothiophene,3-chloro-7-iodo-8-methyldibenzothiophene,3,7-dibromo-8-methyldibenzothiophene,3-bromo-7-iodo-8-methyldibenzothiophene,3,7-diiodo-8-methyldibenzothiophene,7-chloro-2,8-dimethyldibenzothiophene-3-ol,7-bromo-2,8-dimethyldibenzothiophene-3-ol,7-iodo-2,8-dimethyldibenzothiophene-3-ol,3,7-dichloro-2,8-dimethyldibenzothiophene,3-bromo-7-chloro-2,8-dimethyldibenzothiophene,3-chloro-7-iodo-2,8-dimethyldibenzothiophene,3,7-dibromo-2,8-dimethyldibenzothiophene,3-bromo-7-iodo-2,8-dimethyldibenzothiophene,3,7-diiodo-2,8-dimethyldibenzothiophene,7-chloro-4-methyldibenzothiophene-3-ol,7-bromo-4-methyldibenzothiophene-3-ol,7-iodo-4-methyldibenzothiophene-3-ol,3,7-dichloro-4-methyldibenzothiophene,3-bromo-7-chloro-4-methyldibenzothiophene,3-chloro-7-iodo-4-methyldibenzothiophene,3,7-dibromo-4-methyldibenzothiophene,3-bromo-7-iodo-4-methyldibenzothiophene,3,7-diiodo-4-methyldibenzothiophene,7-chloro-6-methyldibenzothiophene-3-ol,7-bromo-6-methyldibenzothiophene-3-ol,7-iodo-6-methyldibenzothiophene-3-ol,3,7-dichloro-6-methyldibenzothiophene,3-bromo-7-chloro-6-methyldibenzothiophene,3-chloro-7-iodo-6-methyldibenzothiophene,3,7-dibromo-6-methyldibenzothiophene,3-bromo-7-iodo-6-methyldibenzothiophene,3,7-diiodo-6-methyldibenzothiophene,7-chloro-4,6-dimethyldibenzothiophene-3-ol,7-bromo-4,6-dimethyldibenzothiophene-3-ol,7-iodo-4,6-dimethyldibenzothiophene-3-ol,3,7-dichloro-4,6-dimethyldibenzothiophene,3-bromo-7-chloro-4,6-dimethyldibenzothiophene,3-chloro-7-iodo-4,6-dimethyldibenzothiophene,3,7-dibromo-4,6-dimethyldibenzothiophene,3-bromo-7-iodo-4,6-dimethyldibenzothiophene,3,7-diiodo-4,6-dimethyldibenzothiophene,7-chloro-2,4-dimethyldibenzothiophene-3-ol,7-bromo-2,4-dimethyldibenzothiophene-3-ol,7-iodo-2,4-dimethyldibenzothiophene-3-ol,3,7-dichloro-2,4-dimethyldibenzothiophene,3-bromo-7-chloro-2,4-dimethyldibenzothiophene,3-chloro-7-iodo-2,4-dimethyldibenzothiophene,3,7-dibromo-2,4-dimethyldibenzothiophene,7-chloro-2,6-dimethyldibenzothiophene-3-ol,7-bromo-2,6-dimethyldibenzothiophene-3-ol,7-iodo-2,6-dimethyldibenzothiophene-3-ol,3,7-dichloro-2,6-dimethyldibenzothiophene,3-bromo-7-chloro-2,6-dimethyldibenzothiophene,3-chloro-7-iodo-2,6-dimethyldibenzothiophene,3,7-dibromo-2,6-dimethyldibenzothiophene,7-chloro-6,8-dimethyldibenzothiophene-3-ol,7-bromo-6,8-dimethyldibenzothiophene-3-ol,7-iodo-6,8-dimethyldibenzothiophene-3-ol,3,7-dichloro-6,8-dimethyldibenzothiophene,3-bromo-7-chloro-6,8-dimethyldibenzothiophene,3-chloro-7-iodo-6,8-dimethyldibenzothiophene,3,7-dibromo-6,8-dimethyldibenzothiophene,7-chloro-4,8-dimethyldibenzothiophene-3-ol,7-bromo-4,8-dimethyldibenzothiophene-3-ol,7-iodo-4,8-dimethyldibenzothiophene-3-ol,3,7-dichloro-4,8-dimethyldibenzothiophene,3-bromo-7-chloro-4,8-dimethyldibenzothiophene,3-chloro-7-iodo-4,8-dimethyldibenzothiophene,3,7-dibromo-4,8-dimethyldibenzothiophene,7-chloro-2,4,6,-trimethyldibenzothiophene-3-ol,7-bromo-2,4,6-trimethyldibenzothiophene-3-ol,7-iodo-2,4,6-trimethyldibenzothiophene-3-ol,3,7-dichloro-2,4,6-trimethyldibenzothiophene,3-bromo-7-chloro-2,4,6-trimethyldibenzothiophene,3-chloro-7-iodo-2,4,6-trimethyldibenzothiophene,3,7-dibromo-2,4,6,-trimethyldibenzothiophene,7-chloro-2,4,8-trimethyldibenzothiophene-3-ol,7-bromo-2,4,8-trimethyldibenzothiophene-3-ol,7-iodo-2,4,8-trimethyldibenzothiophene-3-ol,3,7-dichloro-2,4,8-trimethyldibenzothiophene,3-bromo-7-chloro-2,4,8-trimethyldibenzothiophene,3-chloro-7-iodo-2,4,8-trimethyldibenzothiophene,3,7-dibromo-2,4,8-trimethyldibenzothiophene,7-chloro-2,6,8-trimethyldibenzothiophene-3-ol,7-bromo-2,6,8-trimethyldibenzothiophene-3-ol,7-iodo-2,6,8-trimethyldibenzothiophene-3-ol,3,7-dichloro-2,6,8,-trimethyldibenzothiophene,3-bromo-7-chloro-2,6,8-trimethyldibenzothiophene,3-chloro-7-iodo-2,6,8-trimethyldibenzothiophene,3,7-dibromo-2,6,8-trimethyldibenzothiophene,7-chloro-4,6,8-trimethyldibenzothiophene-3-ol,7-bromo-4,6,8-trimethyldibenzothiophene-3-ol,7-iodo-4,6,8-trimethyldibenzothiophene-3-ol,3,7-dichloro-4,6,8-trimethyldibenzothiophene,3-bromo-7-chloro-4,6,8-trimethyldibenzothiophene,3-chloro-7-iodo-4,6,8-trimethyldibenzothiophene,3,7-dibromo-4,6,8,-trimethyldibenzothiophene,7-chloro-2,4,6,8-tetramethyldibenzothiophene-3-ol,7-bromo-2,4,6,8-tetramethyldibenzothiophene-3-ol,7-iodo-2,4,6,8-tetramethyldibenzothiophene-3-ol,3,7-dichloro-2,4,6,8-tetramethyldibenzothiophene,3-bromo-7-chloro-2,4,6,8-tetramethyldibenzothiophene,3-chloro-7-iodo-2,4,6,8-tetramethyldibenzothiophene,3,7-dibromo-2,4,6,8-tetramethyldibenzothiophene,7-chloro-2-ethyldibenzothiophene-3-ol,7-bromo-2-ethyldibenzothiophene-3-ol,7-iodo-2-ethyldibenzothiophene-3-ol,3,7-dichloro-2-ethyldibenzothiophene,3-bromo-7-chloro-2-ethyldibenzothiophene,3-chloro-7-iodo-2-ethyldibenzothiophene,3,7-dibromo-2-ethyldibenzothiophene,3-bromo-7-iodo-2-ethyldibenzothiophene,3,7-diiodo-2-ethyldibenzothiophene,7-chloro-8-ethyldibenzothiophene-3-ol,7-bromo-8-ethyldibenzothiophene-3-ol,7-iodo-8-ethyldibenzothiophene-3-ol,3,7-dichloro-8-ethyldibenzothiophene,3-bromo-7-chloro-8-ethyldibenzothiophene,3-chloro-7-iodo-8-ethyldibenzothiophene,3,7-dibromo-8-ethyldibenzothiophene,3-bromo-7-iodo-8-ethyldibenzothiophene,3,7-diiodo-8-ethyldibenzothiophene,7-chloro-2,8-diethyldibenzothiophene-3-ol,7-bromo-2,8-diethyldibenzothiophene-3-ol,7-iodo-2,8-diethyldibenzothiophene-3-ol,3,7-dichloro-2,8-diethyldibenzothiophene,3-bromo-7-chloro-2,8-diethyldibenzothiophene,3-chloro-7-iodo-2,8-diethyldibenzothiophene,3,7-dibromo-2,8-diethyldibenzothiophene,3-bromo-7-iodo-2,8-diethyldibenzothiophene,3,7-diiodo-2,8-diethyldibenzothiophene,7-chloro-4-ethyldibenzothiophene-3-ol,7-bromo-4-ethyldibenzothiophene-3-ol,7-iodo-4-ethyldibenzothiophene-3-ol,3,7-dichloro-4-ethyldibenzothiophene,3-bromo-7-chloro-4-ethyldibenzothiophene,3-chloro-7-iodo-4-ethyldibenzothiophene,3,7-dibromo-4-ethyldibenzothiophene,3-bromo-7-iodo-4-ethyldibenzothiophene,3,7-diiodo-4-ethyldibenzothiophene,7-chloro-6-ethyldibenzothiophene-3-ol,7-bromo-6-ethyldibenzothiophene-3-ol,7-iodo-6-ethyldibenzothiophene-3-ol,3,7-dichloro-6-ethyldibenzothiophene,3-bromo-7-chloro-6-ethyldibenzothiophene,3-chloro-7-iodo-6-ethyldibenzothiophene,3,7-dibromo-6-ethyldibenzothiophene,3-bromo-7-iodo-6-ethyldibenzothiophene,3,7-diiodo-6-ethyldibenzothiophene,7-chloro-4,6-diethyldibenzothiophene-3-ol,7-bromo-4,6-diethyldibenzothiophene-3-ol,7-iodo-4,6-diethyldibenzothiophene-3-ol,3,7-dichloro-4,6-diethyldibenzothiophene,3-bromo-7-chloro-4,6-diethyldibenzothiophene,3-chloro-7-iodo-4,6-diethyldibenzothiophene,3,7-dibromo-4,6-diethyldibenzothiophene,3-bromo-7-iodo-4,6-diethyldibenzothiophene,3,7-diiodo-4,6-diethyldibenzothiophene,7-chloro-2,4-diethyldibenzothiophene-3-ol,7-bromo-2,4-diethyldibenzothiophene-3-ol,7-iodo-2,4-diethyldibenzothiophene-3-ol,3,7-dichloro-2,4-diethyldibenzothiophene,3-bromo-7-chloro-2,4-diethyldibenzothiophene,3-chloro-7-iodo-2,4-diethyldibenzothiophene,3,7-dibromo-2,4-diethyldibenzothiophene,7-chloro-2,6-diethyldibenzothiophene-3-ol,7-bromo-2,6-diethyldibenzothiophene-3-ol,7-iodo-2,6-diethyldibenzothiophene-3-ol,3,7-dichloro-2,6-diethyldibenzothiophene,3-bromo-7-chloro-2,6-diethyldibenzothiophene,3-chloro-7-iodo-2,6-diethyldibenzothiophene,3,7-dibromo-2,6-diethyldibenzothiophene,7-chloro-6,8-diethyldibenzothiophene-3-ol,7-bromo-6,8-diethyldibenzothiophene-3-ol,7-iodo-6,8-diethyldibenzothiophene-3-ol,3,7-dichloro-6,8-diethyldibenzothiophene,3-bromo-7-chloro-6,8-diethyldibenzothiophene,3-chloro-7-iodo-6,8-diethyldibenzothiophene,3,7-dibromo-6,8-diethyldibenzothiophene,7-chloro-4,8-diethyldibenzothiophene-3-ol,7-bromo-4,8-diethyldibenzothiophene-3-ol,7-iodo-4,8-diethyldibenzothiophene-3-ol,3,7-dichloro-4,8-diethyldibenzothiophene,3-bromo-7-chloro-4,8-diethyldibenzothiophene,3-chloro-7-iodo-4,8-diethyldibenzothiophene,3,7-dibromo-4,8-diethyldibenzothiophene,7-chloro-2,4,6-triethyldibenzothiophene-3-ol,7-bromo-2,4,6-triethyldibenzothiophene-3-ol,7-iodo-2,4,6-triethyldibenzothiophene-3-ol,3,7-dichloro-2,4,6-triethyldibenzothiophene,3-bromo-7-chloro-2,4,6-triethyldibenzothiophene,3-chloro-7-iodo-2,4,6-triethyldibenzothiophene,3,7-dibromo-2,4,6-triethyldibenzothiophene,7-chloro-2,4,8-triethyldibenzothiophene-3-ol,7-bromo-2,4,8-triethyldibenzothiophene-3-ol,7-iodo-2,4,8-triethyldibenzothiophene-3-ol,3,7-dichloro-2,4,8-triethyldibenzothiophene,3-bromo-7-chloro-2,4,8-triethyldibenzothiophene,3-chloro-7-iodo-2,4,8-triethyldibenzothiophene,3,7-dibromo-2,4,8-triethyldibenzothiophene,7-chloro-2,6,8-triethyldibenzothiophene-3-ol,7-bromo-2,6,8-triethyldibenzothiophene-3-ol,7-iodo-2,6,8-triethyldibenzothiophene-3-ol,3,7-dichloro-2,6,8-triethyldibenzothiophene,3-bromo-7-chloro-2,6,8-triethyldibenzothiophene,3-chloro-7-iodo-2,6,8-triethyldibenzothiophene,3,7-dibromo-2,6,8-triethyldibenzothiophene,7-chloro-4,6,8-triethyldibenzothiophene-3-ol,7-bromo-4,6,8-triethyldibenzothiophene-3-ol,7-iodo-4,6,8-triethyldibenzothiophene-3-ol,3,7-dichloro-4,6,8-triethyldibenzothiophene,3-bromo-7-chloro-4,6,8-triethyldibenzothiophene,3-chloro-7-iodo-4,6,8-triethyldibenzothiophene,3,7-dibromo-4,6,8-triethyldibenzothiophene,7-chloro-2,4,6,8-tetraethyldibenzothiophene-3-ol,7-bromo-2,4,6,8-tetraethyldibenzothiophene-3-ol,7-iodo-2,4,6,8-tetraethyldibenzothiophene-3-ol,3,7-dichloro-2,4,6,8-tetraethyldibenzothiophene,3-bromo-7-chloro-2,4,6,8-tetraethyldibenzothiophene,3-chloro-7-iodo-2,4,6,8-tetraethyldibenzothiophene,3,7-dibromo-2,4,6,8-tetraethyldibenzothiophene,7-chloro-2-trifluoromethyldibenzothiophene-3-ol,7-bromo-2-trifluoromethyldibenzothiophene-3-ol,7-iodo-2-trifluoromethyldibenzothiophene-3-ol,3,7-dichloro-2-trifluoromethyldibenzothiophene,3-bromo-7-chloro-2-trifluoromethyldibenzothiophene,3-chloro-7-iodo-2-trifluoromethyldibenzothiophene,3,7-dibromo-2-trifluoromethyldibenzothiophene,3-bromo-7-iodo-2-trifluoromethyldibenzothiophene,3,7-diiodo-2-trifluoromethyldibenzothiophene,7-chloro-8-trifluoromethyldibenzothiophene-3-ol,7-bromo-8-trifluoromethyldibenzothiophene-3-ol,7-iodo-8-trifluoromethyldibenzothiophene-3-ol,3,7-dichloro-8-trifluoromethyldibenzothiophene,3-bromo-7-chloro-8-trifluoromethyldibenzothiophene,3-chloro-7-iodo-8-trifluoromethyldibenzothiophene,3,7-dibromo-8-trifluoromethyldibenzothiophene,3-bromo-7-iodo-8-trifluoromethyldibenzothiophene,3,7-diiodo-8-trifluoromethyldibenzothiophene,7-chloro-2,8-bis(trifluoromethyl)dibenzothiophene-3-ol,7-bromo-2,8-bis(trifluoromethyl)dibenzothiophene-3-ol,7-iodo-2,8-bis(trifluoromethyl)dibenzothiophene-3-ol,3,7-dichloro-2,8-bis(trifluoromethyl)dibenzothiophene,3-bromo-7-chloro-2,8-bis(trifluoromethyl)dibenzothiophene,3-chloro-7-iodo-2,8-bis(trifluoromethyl)dibenzothiophene,3,7-dibromo-2,8-bis(trifluoromethyl)dibenzothiophene,3-bromo-7-iodo-2,8-bis(trifluoromethyl)dibenzothiophene,3,7-diiodo-2,8-bis(trifluoromethyl)dibenzothiophene,7-chloro-4-trifluoromethyldibenzothiophene-3-ol,7-bromo-4-trifluoromethyldibenzothiophene-3-ol,7-iodo-4-trifluoromethyldibenzothiophene-3-ol,3,7-dichloro-4-trifluoromethyldibenzothiophene,3-bromo-7-chloro-4-trifluoromethyldibenzothiophene,3-chloro-7-iodo-4-trifluoromethyldibenzothiophene,3,7-dibromo-4-trifluoromethyldibenzothiophene,3-bromo-7-iodo-4-trifluoromethyldibenzothiophene,3,7-diiodo-4-trifluoromethyldibenzothiophene,7-chloro-6-trifluoromethyldibenzothiophene-3-ol,7-bromo-6-trifluoromethyldibenzothiophene-3-ol,7-iodo-6-trifluoromethyldibenzothiophene-3-ol,3,7-dichloro-6-trifluoromethyldibenzothiophene,3-bromo-7-chloro-6-trifluoromethyldibenzothiophene,3-chloro-7-iodo-6-trifluoromethyldibenzothiophene,3,7-dibromo-6-trifluoromethyldibenzotiophene,3-bromo-7-iodo-6-trifluoromethyldibenzothiophene,3,7-diiodo-6-trifluoromethyldibenzothiophene,7-chloro-4,6-bis(trifluoromethyl)dibenzothiophene-3-ol,7-bromo-4,6-bis(trifluoromethyl)dibenzothiophene-3-ol,7-iodo-4,6-bis(trifluoromethyl)dibenzothiophene-3-ol,3,7-dichloro-4,6-bis(trifluoromethyl)dibenzothiophene,3-bromo-7-chloro-4,6-bis(trifluoromethyl)dibenzothiophene,3-chloro-7-iodo-4,6-bis(trifluoromethyl)dibenzothiophene,3,7-dibromo-4,6-bis(trifluoromethyl)dibenzothiophene,3-bromo-7-iodo-4,6-bis(trifluoromethyl)dibenzothiophene,3,7-diiodo-4,6-bis(trifluoromethyl)dibenzothiophene,7-chloro-2,4-bis(trifluoromethyl)dibenzothiophene-3-ol,7-bromo-2,4-bis(trifluoromethyl)dibenzothiophene-3-ol,7-iodo-2,4-bis(trifluoromethyl)dibenzothiophene-3-ol,3,7-dichloro-2,4-bis(trifluoromethyl)dibenzothiophene,3-bromo-7-chloro-2,4-bis(trifluoromethyl)dibenzothiophene,3-chloro-7-iodo-2,4-bis(trifluoromethyl)dibenzothiophene,3,7-dibromo-2,4-bis(trifluoromethyl)dibenzothiophene,7-chloro-2,6-bis(trifluoromethyl)dibenzothiophene-3-ol,7-bromo-2,6-bis(trifluoromethyl)dibenzothiophene-3-ol,7-iodo-2,6-bis(trifluoromethyl)dibenzothiophene-3-ol,3,7-dichloro-2,6-bis(trifluoromethyl)dibenzothiophene,3-bromo-7-chloro-2,6-bis(trifluoromethyl)dibenzothiophene,3-chloro-7-iodo-2,6-bis(trifluoromethyl)dibenzothiophene,3,7-dibromo-2,6-bis(trifluoromethyl)dibenzothiophene,7-chloro-6,8-bis(trifluoromethyl)dibenzothiophene-3-ol,7-bromo-6,8-bis(trifluoromethyl)dibenzothiophene-3-ol,7-iodo-6,8-bis(trifluoromethyl)dibenzothiophene-3-ol,3,7-dichloro-6,8-bis(trifluoromethyl)dibenzothiophene,3-bromo-7-chloro-6,8-bis(trifluoromethyl)dibenzothiophene,3-chloro-7-iodo-6,8-bis(trifluoromethyl)dibenzothiophene,3,7-dibromo-6,8-bis(trifluoromethyl)dibenzothiophene,7-chloro-4,8-bis(trifluoromethyl)dibenzothiophene-3-ol,7-bromo-4,8-bis(trifluoromethyl)dibenzothiophene-3-ol,7-iodo-4,8-bis(trifluoromethyl)dibenzothiophene-3-ol,3,7-dichloro-4,8-bis(trifluoromethyl)dibenzothiophene,3-bromo-7-chloro-4,8-bis(trifluoromethyl)dibenzothiophene,3-chloro-7-iodo-4,8-bis(trifluoromethyl)dibenzothiophene,3,7-dibromo-4,8-bis(trifluoromethyl)dibenzothiophene,7-chloro-2,4,6-tris(trifluoromethyl)dibenzothiophene-3-ol,7-bromo-2,4,6-tris(trifluoromethyl)dibenzothiophene-3-ol,7-iodo-2,4,6-tris(trifluoromethyl)dibenzothiophene-3-ol,3,7-dichloro-2,4,6-tris(trifluoromethyl)dibenzothiophene,3-bromo-7-chloro-2,4,6-tris(trifluoromethyl)dibenzothiophene,3-chloro-7-iodo-2,4,6-tris(trifluoromethyl)dibenzothiophene,3,7-dibromo-2,4,6-tris(trifluoromethyl)dibenzothiophene,7-chloro-2,4,8-tris(trifluoromethyl)dibenzothiophene-3-ol,7-bromo-2,4,8-tris(trifluoromethyl)dibenzothiophene-3-ol,7-iodo-2,4,8-tris(trifluoromethyl)dibenzothiophene-3-ol,3,7-dichloro-2,4,8-tris(trifluoromethyl)dibenzothiophene,3-bromo-7-chloro-2,4,8-tris(trifluoromethyl)dibenzothiophene,3-chloro-7-iodo-2,4,8-tris(trifluoromethyl)dibenzothiophene,3,7-dibromo-2,4,8-tris(trifluoromethyl)dibenzothiophene,7-chloro-2,6,8-tris(trifluoromethyl)dibenzothiophene-3-ol,7-bromo-2,6,8-tris(trifluoromethyl)dibenzothiophene-3-ol,7-iodo-2,6,8-tris(trifluoromethyl)dibenzothiophene-3-ol,3,7-dichloro-2,6,8-tris(trifluoromethyl)dibenzothiophene,3-bromo-7-chloro-2,6,8-tris(trifluoromethyl)dibenzothiophene,3-chloro-7-iodo-2,6,8-tris(trifluoromethyl)dibenzothiophene,3,7-dibromo-2,6,8-tris(trifluoromethyl)dibenzothiophene,7-chloro-4,6,8-tris(trifluoromethyl)dibenzothiophene-3-ol,7-bromo-4,6,8-tris(trifluoromethyl)dibenzothiophene-3-ol,7-iodo-4,6,8-tris(trifluoromethyl)dibenzothiophene-3-ol,3,7-dichloro-4,6,8-tris(trifluoromethyl)dibenzothiophene,3-bromo-7-chloro-4,6,8-tris(trifluoromethyl)dibenzothiophene,3-chloro-7-iodo-4,6,8-tris(trifluoromethyl)dibenzothiophene,3,7-dibromo-4,6,8-tris(trifluoromethyl)dibenzothiophene,7-chloro-2,4,6,8-tetrakis(trifluoromethyl)dibenzothiophene-3-ol,7-bromo-2,4,6,8-tetrakis(trifluoromethyl)dibenzothiophene-3-ol,7-iodo-2,4,6,8-tetrakis(trifluoromethyl)dibenzothiophene-3-ol,3,7-dichloro-2,4,6,8-tetrakis(trifluoromethyl)dibenzothiophene,3-bromo-7-chloro-2,4,6,8-tetrakis(trifluoromethyl)dibenzothiophene,3-chloro-7-iodo-2,4,6,8-tetrakis(trifluoromethyl)dibenzothiophene, and3,7-dibromo-2,4,6,8-tetrakis(trifluoromethyl)dibenzothiophene.

The dibenzothiophene compound (A-1) of the present invention may beprepared by diazotizing a dibenzothiophene compound (A-2) to obtain adiazonium salt, and decomposing the diazonium salt in the presence of ananion Y corresponding to Y in the formula (A-1).

The diazotization of a dibenzothiophene compound (A-2) and decompositionof the resulting diazonium salt in the presence of an anion Y may becarried out through publicly known techniques, such as those describedin Org. Synth. C.V.1, 404, Org. Synth. C.V.3, 130, or Chem. Ber. 1951,84, 557.

A diazotizing reagent used in the above method may be, for example,nitric acid, nitrosylsulfuric acid, or sodium nitrite. The amount of thediazotizing reagent is not particularly limited, and usually about 1 to100 times, preferably about 1 to 10 times the amount of thedibenzothiophene compound (A-2) in mole.

The diazotization of the dibenzothiophene compound (A-2) is usuallycarried out in an inert gas atmosphere, such as of argon or nitrogen.

The reaction may be proceeded either without or in a solvent. Thesolvent may be, for example, a halogenated hydrocarbon such asdichloromethane, chloroform, or 1,2-dichloroethane; an aliphatichydrocarbon such as hexane, heptane, octane, or nonane; an aromatichydrocarbon such as benzene, toluene, xylene, or chlorobenzene; an ethersolvent such as diethyl ether or tetrahydrofuran; an organic acid suchas acetic acid or methanesulfonic acid; a mineral acid such as nitricacid or sulfuric acid; water; or mixtures thereof.

The reaction temperature for the diazotization is not particularlylimited, and is usually −50 to 100° C., preferably −30 to 50° C.

The diazotization results a diazonium salt, which is used in thefollowing diazo decomposition process usually in the form of anas-obtained reaction mixture, due to its poor stability. The diazoniumsalt may, however, readily be separated from the reaction mixture, ifnecessary, through ordinary processes including distillation,recrystallization, column chromatography, or the like.

The generated diazonium salt is then decomposed in the presence of ananion Y, which may be donated by, for example, water, copper (I)chloride, copper (I) bromide, hydrogen chloride, or hydrogen bromide.The amount of the donor of the anion Y used in the reaction is notparticularly limited, but is usually 1 to 100 times, preferably 1 to 10times the amount of dibenzothiophene compound (A-2) in mole.

The decomposition of the diazonium salt in the presence of an anion Ymay usually be carried out in an inert gas atmosphere, such as of argonor nitrogen. The reaction may be proceeded either without or in asolvent, which may preferably be selected from those mentioned above foruse in diazotization of the dibenzothiophene compound (A-2).

The reaction temperature for the decomposition is not particularlylimited, and is usually about −50 to 200° C., preferably about −30 to150° C.

The dibenzothiophene compound (A-1) thus formed may readily be separatedfrom the reaction mixture through ordinary processes, if necessary,including extraction with an organic solvent, washing with water,distillation, recrystallization, column chromatography, or the like.

In the formula (A-2) representing the dibenzothiophene compound (A-2) ofthe present invention used in manufacture of the dibenzothiophenecompound (A-1), A¹ to A⁶ and X mean the same as those in the formula(A-1). Specific examples of the dibenzothiophene compound (A-2) mayinclude compounds having A¹ to A⁶ and X corresponding to those in thedibenzothiophene compound (A-1).

The dibenzothiophene compound (A-2) may be prepared by reducing adibenzothiophene oxide compound (A-3). In the reaction, the twofunctional groups, sulfoxide and nitro groups, are reduced either one byone or simultaneously.

The reduction of a dibenzothiophene oxide compound (A-3) may be carriedout, for example, by a conventional technique such as disclosed in J.Am. Chem. Soc. 1952, 74, 1165.

For reducing the dibenzothiophene oxide compound (A-3), a reducing agentmay be used, which may be, for example, tin (II) chloride or iron. Theamount of the reducing agent is not particularly limited, and is usuallyabout 1 to 100 times, preferably about 1 to 10 times the amount of thedibenzothiophene oxide compound (A-3) in mole.

The reduction of a dibenzothiophene oxide compound (A-3) may usually becarried out in an inert gas atmosphere, such as of argon or nitrogen.The reaction may be proceeded either without or in a solvent, which maypreferably be selected from those mentioned above for use indiazotization of the dibenzothiophene compound (A-2).

The reaction temperature for the reduction is not particularly limited,and is usually about −50 to 200° C., preferably about −30 to 150° C.

The dibenzothiophene compound (A-2) resulting from the reduction mayreadily be separated from the reaction mixture, if necessary, throughordinary processes including extraction with an organic solvent, washingwith water, distillation, recrystallization, column chromatography, orthe like.

In the formula (A-3) representing the dibenzothiophene oxide compound(A-3) of the present invention used in manufacture of thedibenzothiophene compound (A-2), A¹ to A⁶ and X mean the same as thosein the formula (A-1). Specific examples of the dibenzothiophene oxidecompound (A-3) may include compounds having A¹ to A⁶ and X correspondingto those in the dibenzothiophene compound (A-1).

The dibenzothiophene oxide compound (A-3) of the present invention maybe prepared by nitrating a dibenzothiophene oxide compound (A-4), whichmay be carried out, for example, by a conventional technique such asdisclosed in J. Am. Chem. Soc. 1952, 74, 1165.

For nitrating the dibenzothiophene oxide compound (A-4), a nitratingagent may be used, which may be selected from, for example, nitrates ornitrites of sodium, potassium, or silver; alkyl nitrates such as butylor amyl nitrate; or nitric acid.

The amount of the nitrating agent is not particularly limited, and isusually about 1 to 100 times, preferably about 1 to 10 times the amountof the dibenzothiophene oxide compound (A-4) in mole.

The nitration of a dibenzothiophene oxide compound (A-4) may usually becarried out in an inert gas atmosphere, such as of argon or nitrogen.The reaction may be proceeded either without or in a solvent, which maypreferably be selected from those mentioned above for use indiazotization of the dibenzothiophene compound (A-2).

The reaction temperature for the nitration is not particularly limited,and is usually about −50 to 200° C., preferably −30 to 150° C.

The dibenzothiophene oxide compound (A-3) resulting from the nitrationmay readily be separated from the reaction mixture, if necessary,through ordinary processes including extraction with an organic solvent,washing with water, distillation, recrystallization, columnchromatography, or the like.

In the formula (A-4) representing the dibenzothiophene oxide compound(A-4) of the present invention used in manufacture of thedibenzothiophene oxide compound (A-3), A¹ to A⁶ and X mean the same asthose in the formula (A-1). Specific examples of the dibenzothiopheneoxide compound (A-4) may include compounds having A¹ to A⁶ and Xcorresponding to those in the dibenzothiophene compound (A-1).

The dibenzothiophene oxide compound (A-4) of the present invention maybe prepared by oxidizing a dibenzothiophene compound (A-5), which may becarried out, for example, by a conventional technique such as disclosedin J. Am. Chem. Soc. 1948, 70, 1748.

For oxidation of the dibenzothiophene compound (A-5), an oxidizing agentmay be used, which may be selected from, for example, organic peroxidessuch as m-chloroperbenzoic acid; perhalides such as sodium periodate; amixture of chlorine and water; or hydrogen peroxide.

The amount of the oxidizing agent is not particularly limited, and isusually about 1 to 100 times, preferably about 1 to 10 times the amountof the dibenzothiophene compound (A-5) in mole.

The oxidation of dibenzothiophene compound (A-5) may usually be carriedout in an inert gas atmosphere, such as of argon or nitrogen. Thereaction may be proceeded either without or in a solvent, which maypreferably be selected from those mentioned above for use indiazotization of the dibenzothiophene compound (A-2).

The reaction temperature for the oxidation is not particularly limited,and is usually about −50 to 200° C., preferably −30 to 150° C.

The dibenzothiophene oxide compound (A-4) resulting from the oxidationmay readily be separated from the reaction mixture, if necessary,through ordinary processes including extraction with an organic solvent,washing with water, distillation, recrystallization, columnchromatography, or the like.

EXAMPLES

The present invention will now be explained in detail with reference toExamples, but the present invention is not limited thereto.

A series of reactions to be discussed in Examples 1-1 to 1-4 below maybe expressed as follows:

Example 1-1

According to the process disclosed in J. Am. Chem. Soc., 1951, 73, 5887,3-bromodibenzothiophene was synthesized. A flask equipped with a stirrerand a thermometer was charged with 44.1 g of the thus synthesized3-bromodibenzothiophene and 441 g of carbon tetrachloride in a nitrogenatmosphere, and cooled to −5° C. The mixture was bubbled with a chlorinegas under stirring at −7° C. to −12° C. for 5 hours. The reaction masswas poured into 1000 g of ice water, and stirred at or below 5° C. for40 minutes. The reactant was filtered and washed with carbontetrachloride. The resulting crystals were dried to obtain 27.91 g of3-bromodibenzothiophene-5-oxide. The product was subjected to elementalanalysis, the results of which are as follows:

Elemental Analysis: C₁₂H₇BrOS (Theoretical(%): C=51.63, H=2.53;Observed(%): C=51.59, H=2.58).

Example 1-2

A flask equipped with a stirrer and a thermometer was charged with 69.8g of glacial acetic acid and 27.9 g of 3-bromodibenzothiophene-5-oxideprepared in Example 1-1 in a nitrogen atmosphere, and cooled to 10° C.239.8 g of concentrated sulfuric acid was added dropwise, and theresulting mixture was cooled to −2° C. Then 72.0 g of 70 wt % nitricacid was added dropwise at −2 to 8° C., and the resulting mixture wasstirred at or below 5° C. for 2 hours. The reaction mass was poured into1200 g of ice water to terminate the reaction, and stirred further. Thereactant was filtered, washed with water, and dried. The resulting drycake was washed with ethanol to obtain 31.9 g of3-bromo-7-nitrodibenzothiophene-5-oxide. The product was subjected toelemental analysis, the results of which are as follows:

Elemental Analysis: C₁₂H₆BrNO₃S (Theoretical(%): C=44.46, H=1.87;Observed(%): C=44.42, H=1.84).

Example 1-3

A flask equipped with a stirrer and a thermometer was charged with 26.98g of the intermediate 3-bromo-7-nitrodibenzothiophene-5-oxide preparedin Example 1-2 and 269.8 g of glacial acetic acid in a nitrogenatmosphere. 112.7 g of SnCl₂.2H₂O dissolved in 158 g of concentratedhydrochloric acid was added dropwise at 14 to 18° C. over 1 hour, andstirred overnight at room temperature. The resulting reactant wasfiltered, washed with 1:1 glacial acetic acid/concentrated hydrochloricacid, and neutralized with 1100 g of a 7 wt % aqueous solution of sodiumhydroxide. The reactant was extracted with ethyl acetate, washed withwater, concentrated, and purified by silica gel chromatography using 1:1hexane/chloroform mixed with 0.1 wt % triethylamine as an elutingsolvent, to thereby obtain 17.31 g of objective7-bromodibenzothiophene-3-yl-amine. The product was subjected toelemental analysis, the results of which are as follows:

Elemental Analysis: C₁₂H₈BrNS (Theoretical(%): C=51.81, H=2.90;Observed(%): C=51.77, H=2.92).

Example 1-4

A flask equipped with a stirrer and a thermometer was charged with 209.3g of concentrated sulfuric acid and 8.93 g of NaNO₂ in a nitrogenatmosphere, and cooled to 2° C. Then 24.0 g of the intermediate7-bromodibenzothiophene-3-yl-amine prepared in Example 1-3 was added,and stirred at 2 to 4° C. for 3 hours. The resulting mixture togetherwith 99.8 g of water was poured into 348.7 g of 65 wt % sulfuric acidpreheated to 80° C., stirred at 80 to 85° C. for 5 hours, and cooled toroom temperature. The reactant was filtered, extracted six times with300 ml of ethyl acetate, and vacuum concentrated. The concentrate waspurified by silica gel chromatography using chloroform as an elutingsolvent to obtain 7.11 g of objective 7-bromodibenzothiophene-3-ol. The¹H-NMR spectrum data and the results of elemental analysis of theproduct are shown below:

¹H-NMR (CDCl₃, δ): 4.98 (s, 1H), 6.95-7.00 (m, 1H), 7.25-7.27 (m, 1H),7.50-7.54 (m, 1H), 7.84-7.88 (m, 1H), 7.91-7.93 (m, 1H), 7.93-7.97 (m,1H)

Elemental Analysis: C₁₂H₇BrOS (Theoretical(%): C=51.63, H=2.53;Observed(%): C=51.58, H=2.55).

Production Example 2-1

A flask equipped with a stirrer and a thermometer was charged with 27.64g of a starting material RDBT-1 and 276.4 g of carbon tetrachloride in anitrogen atmosphere, and cooled to 2° C. The mixture was bubbled with achlorine gas under stirring for 5 hours. The reaction mass was pouredinto 400 g of ice water, and stirred for 50 minutes. The reactant wasfiltered and washed with water. The filtrate was concentrated, andrepulped with 1:1 toluene/hexane, to thereby obtain 18.53 g of IMDBT-1.

A flask equipped with a stirrer and a thermometer was charged with 164.5g of glacial acetic acid in a nitrogen atmosphere, and cooled to 5° C.Then 549.3 g of sulfuric acid was added dropwise, and heated to 23 to25° C. 65.8 g of an intermediate IMDBT-1 was added and dissolved, andcooled to 5 to 9° C. 236.6 g of 70 wt % nitric acid was added dropwise,and stirred for 2 hours. The reaction mass was poured into 2745 g of icewater to terminate the reaction, and stirred further. The reactant wasfiltered, washed with water, and dried. The dry cake thus obtained wasrepulped with ethanol to obtain 69 g of IMDBT-2.

A flask equipped with a stirrer and a thermometer was charged with 69.0g of the intermediate IMDBT-2 prepared above and 690.0 g of glacialacetic acid in a nitrogen atmosphere, to which 320.1 g of SnCl₂dissolved in 439.5 g of concentrated hydrochloric acid was addeddropwise at 24 to 33° C., and stirred overnight at room temperature. Thereactant was filtered, washed with 1:1 glacial acetic acid/concentratedhydrochloric acid, and neutralized with 600 g of a 10% aqueous solutionof sodium hydroxide. The reactant was extracted with ethyl acetate,washed with water, concentrated, and purified by silica gelchromatography using chloroform as an eluting solvent, to thereby obtain48.0 g of IMDBT-3.

A flask equipped with a stirrer and a thermometer was charged with 182.8g of 98 wt % sulfuric acid and 18.28 g of NaNO₂ in a nitrogenatmosphere, and cooled to 2° C. Then 48.0 g of the intermediate IMDBT-3prepared above dissolved in 576 g of glacial acetic acid was addeddropwise, and stirred at 5 to 8° C. for 100 minutes. The mixture wascooled to −5° C., mixed with 500 ml of ether, and stirred at −5° C. for25 minutes. The reactant was filtered and washed with ether. Theresulting wet cake was introduced into a vessel charged at roomtemperature with 1037 g of a 48% aqueous solution of HBr and 51.84 g ofCuBr, stirred at 25 to 64° C. for 30 minutes, refluxed at 64° C. for 2hours, filtered, and washed with water. The resulting wet case wasdried, and subjected to silica gel chromatography using hexane as aneluting solvent, to thereby obtain 41.8 g of IMDBT-4.

A flask equipped with a stirrer and a thermometer was charged with 10.53g of the intermediate IMDBT-4 prepared above, 0.21 g ofdichlorobis(triphenylphosphine)palladium, 0.21 g of triphenylphosphine,0.11 g of copper iodide, and 40.5 g of triethylamine in a nitrogenatmosphere, and heated to 76° C. Then 5.05 g of 2-methyl-3-butyne-2-oldissolved in 2.5 g of ethyl acetate was added dropwise, and stirred for2 hours. The reactant was filtered, and washed with ethyl acetate. Thefiltrate was concentrated, and purified by silica gel chromatographyusing 5:1 hexane/ethyl acetate mixed with 0.1 wt % triethylamine as aneluting solvent, to thereby obtain 9.75 g of IMDBT-5.

A flask equipped with a stirrer and a thermometer was charged with 9.75g of the intermediate IMDBT-5 prepared above, 48.8 g of toluene, and 0.4g of KOH in a nitrogen atmosphere, heated to 95° C., and stirred for 3hours. After the termination of the reaction, the reactant wasconcentrated, and purified by silica gel chromatography using hexanemixed with 0.1 wt % triethylamine as an eluting solvent, to therebyobtain 6.60 g of objective IMDBT-6. The ¹H-NMR spectrum data of theresulting IMDBT-6, as well as the formulae of the series of reactionsare shown below.

¹H-NMR (CDCl₃, δ): 3.15 (s, 1H), 7.43-7.46 (m, 2H), 7.53-7.56 (m, 1H),7.81-7.84 (m, 1H), 7.97-8.11 (m, 3H)

Production Example 2-2

A flask equipped with a stirrer and a thermometer was charged with 18.95g of IMDBT-4 prepared in Production Example 2-1, 0.387 g ofdichlorobis(triphenylphosphine) palladium, 0.38 g of triphenylphosphine,0.19 g of copper (I) iodide, and 72.9 g of triethylamine in a nitrogenatmosphere, and heated to 76° C. Then 17.41 g of IM-2 dissolved in 9.1 gof ethyl acetate was added dropwise, stirred at 76 to 80° C. for 5hours, and allowed to cool to room temperature. The reactant wasfiltered and washed with ethyl acetate, and the filtrate wasconcentrated. The resulting solid was mixed with 129.6 g of methanol,0.32 g of p-toluenesulfonic acid, and 129.6 g of THF, and stirred at 23to 40° C. for 2.5 hours. After the termination of the reaction, thereaction mixture was neutralized with 2 g of triethylamine, andconcentrated. The concentrate was purified by silica gel chromatographyusing 10:1 hexane/ethyl acetate mixed with 0.1 wt % triethylamine as aneluting solvent, to thereby obtain 14.1 g of intermediate IMDBT-7.

A flask equipped with a stirrer and a thermometer was charged with thethus obtained 14.1 g of the intermediate IMDBT-7 in a nitrogenatmosphere. 70.5 g of toluene, 28.1 g of pyridine, and 0.28 g of4-pyrrolidinopyridine were added, and cooled to −2° C. While stirringthe mixture at the same temperature, 18.17 g of trifluoromethanesulfonicacid anhydride was added dropwise, and stirred at 0 to 2° C. for 1.5hours. After the termination of the reaction, the mixture was mixed withwater, and extracted with ethyl acetate. The resulting organic phase wasconcentrated, and subjected to silica gel chromatography using 20:1hexane/chloroform as an eluting solvent, to thereby obtain 18.64 g ofintermediate IMDBT-8.

The ¹H-NMR spectrum data of the resulting IMDBT-8, as well as theformulae of the series of reactions above are shown below.

¹H-NMR (CDCl₃, δ): 1.29 (t, 3H, J=7.5 Hz), 2.75 (q, 2H, J=7.5 Hz),7.20-7.26 (m, 1H), 7.40-7.60 (m, 5H), 7.81-7.89 (m, 1H), 8.01-8.18 (m,3H)

Example 2-1

A flask equipped with a stirrer and a thermometer was charged with 5.53g of IMDBT-8 prepared in Production Example 2-2, 0.11 g ofdichlorobis(triphenylphosphine) palladium, 3.64 g of triethylamine, and33.2 g of DMF in a nitrogen atmosphere, and heated to 65° C. Then 4.50 gof IMDBT-6 prepared in Production Example 2-1 dissolved in 6.8 g of DMFwas added dropwise, stirred at 63 to 68° C. for 7 hours, and allowed tocool to room temperature. The reactant was filtered and washed withethyl acetate. The wet cake 1 obtained on the filter was preserved.Next, the filtrate was washed with water and concentrated. The resultingsolid was subjected to silica gel chromatography using chloroform mixedwith 0.1 wt % triethylamine as an eluting solvent, repulped with ethylacetate, mixed with the wet cake 1 preserved on the filter, subjected tosilica gel chromatography using 5:1 hexane/chloroform mixed with 0.1 wt% triethylamine as an eluting solvent, and recrystallized fromchloroform, to thereby obtain 2.86 g of objective DBT1116.

The ¹H-NMR spectrum data of the obtained compound DBT1116, as well asthe formulae of the reaction in this Example are shown below.

¹H-NMR (CDCl₃, δ): 1.38 (t, 3H, J=7.5 Hz), 2.95 (q, 2H), 7.37-7.58 (m,7H), 7.58-7.69 (m, 2H), 7.83-7.90 (m, 2H), 8.02-8.08 (m, 2H), 8.11-8.20(m, 4H)

The obtained DBT1116 was theoretically divided into the following parts,and the difference ΔE in energy of HOMO of the parts and thepolarizability anisotropy Δα were calculated by the method of molecularorbitals. The results are as follows:

The phase sequence of the compound DBT1116 was evaluated withpolarization microscope to find that the compound was in the crystallinephase below 227° C., and in the nematic phase from 227° C. When thecompound was further heated to 300° C., it was still in the nematicphase. It was thus demonstrated that this compound was a liquidcrystalline compound. Upon visual observation in its nematic and liquidphases, this compound was transparent and colorless.

5 wt % of the compound DBT1116 was added to a nematic compositionMJ931381 (manufactured by Merck Japan Co.), and the refractive indexanisotropy Δn was determined, from which Δn of the compound wasextrapolated based on the concentration. It was determined that the Δnof the compound was 0.63, which is an extremely large value. Δn wasmeasured with an Abbe refractometer at 20° C. and at the wavelength of589 nm.

Example 2-2

A flask equipped with a stirrer and a thermometer was charged with 5.53g of IMDBT-8 prepared in Production Example 2-2, 0.17 g ofdichlorobis(triphenylphosphine) palladium, 3.64 g of triethylamine, and33.2 g of DMF in a nitrogen atmosphere, and heated to 65° C. Then 3.84 gof IM-1 dissolved in 4.3 g of DMF were added dropwise, stirred at 64 to68° C. for 10 hours, and allowed to cool to room temperature. Thereactant was filtered and washed with ethyl acetate. The residue left onthe filter was concentrated, and the resulting solid was subjected tosilica gel chromatography using chloroform mixed with 0.1 wt %triethylamine as an eluting solvent, repulped with ethyl acetate, andpurified by silica gel chromatography using 10:1 hexane/chloroform mixedwith 0.1 wt % triethylamine as an eluting solvent, to thereby obtain4.18 g of objective DBT1115. The ¹H-NMR spectrum data of the obtainedcompound DBT1115, as well as the formulae of the reaction above areshown below.

¹H-NMR (CDCl₃, δ): 0.94 (t, 3H, J=7.5 Hz), 1.33 (t, 3H, J=7.5 Hz),1.38-1.49 (m, 4H), 1.75-1.85 (m, 2H), 2.90 (q, 2H, J=7.5 Hz), 3.97 (t,2H, J=7.5 Hz), 6.86-6.90 (m, 2H), 7.37-7.63 (m, 8H), 7.85-8.37 (m, 4H)

The obtained DBT1115 was theoretically divided into the following parts,and the difference ΔE in energy of HOMO of the parts and thepolarizability anisotropy Δα were calculated by the method of molecularorbitals. The results are as follows:

The phase sequence of the compound DBT1115 was evaluated withpolarization microscope to find that the compound was in the crystallinephase below 134° C., in the nematic phase in the range of 134 to 253°C., and in the isotropic phase above 253° C. It was thus demonstratedthat this compound was a liquid crystalline compound. Upon visualobservation in its nematic and liquid phases, this compound wastransparent and colorless.

10 wt % of the compound DBT1115 was added to a nematic compositionMJ931381 (manufactured by Merck Japan Co.), and the refractive indexanisotropy Δn was determined, from which Δn of the compound wasextrapolated based on the concentration. It was determined that the Δnof the compound was 0.53, which is an extremely large value. Δn wasmeasured with an Abbe refractometer at 20° C. and at the wavelength of589 nm.

Production Example 2-3

A flask equipped with a stirrer and a thermometer was charged with 44.1g of a starting material IMDBT-4 prepared in Production Example 2-1 and441 g of carbon tetrachloride in a nitrogen atmosphere, and cooled to−5° C. The mixture was bubbled with a chlorine gas under stirring at −7°C. to −12° C. for 5 hours. The reaction mass was poured into 1000 g ofice water, and stirred at or below 5° C. for 40 minutes. The reactantwas filtered and washed with carbon tetrachloride. The resultingcrystals were dried to obtain 27.91 g of IMDBT-9.

A flask equipped with a stirrer and a thermometer was charged with 69.8g of glacial acetic acid and 27.9 g of IMDBT-9 prepared above in anitrogen atmosphere, and cooled to 10° C. Then 239.8 g of concentratedsulfuric acid was added dropwise, and cooled to −2° C. 72.0 g of 70 wt %nitric acid was added dropwise at −2 to 8° C., and stirred at or below5° C. for 2 hours. The resulting mixture was poured into 1200 g of icewater to terminate the reaction, and stirred further. The reactant wasfiltered, washed with water, and dried. The dry cake thus obtained waswashed with ethanol to obtain 31.9 g of IMDBT-10.

A flask equipped with a stirrer and a thermometer was charged with 26.98g of the intermediate IMDBT-10 prepared above and 269.8 g of glacialacetic acid in a nitrogen atmosphere. 112.7 g of SnCl₂.2H₂O dissolved in158 g of concentrated hydrochloric acid was added dropwise at 14 to 18°C. over 1 hour, and stirred overnight at room temperature. The reactantwas filtered, washed with 1:1 glacial acetic acid/concentratedhydrochloric acid, and neutralized with 1100 g of a 7 wt % aqueoussolution of sodium hydroxide. The reactant was extracted with ethylacetate, washed with water, concentrated, and purified by silica gelchromatography using 1:1 hexane/chloroform mixed with 0.1 wt %triethylamine as an eluting solvent, to thereby obtain 17.31 g ofIMDBT-11.

A flask equipped with a stirrer and a thermometer was charged with 209.3g of concentrated sulfuric acid and 8.93 g of NaNO₂ in a nitrogenatmosphere, and cooled to 2° C. Then 24.0 g of the intermediate IMDBT-11prepared above was added, and stirred at 2 to 4° C. for 3 hours. Theresulting mixture together with 99.8 g of water was poured into 348.7 gof 65 wt % sulfuric acid preheated to 80° C., stirred at 80 to 85° C.for 5 hours, and cooled to room temperature. The reactant was filtered,extracted six times with 300 ml of ethyl acetate, and vacuumconcentrated. The concentrate was purified by silica gel chromatographyusing chloroform as an eluting solvent to obtain 7.11 g of IMDBT-12. The¹H-NMR spectrum data of the resulting IMDBT-12 are shown below.

¹H-NMR (CDCl₃, δ): 4.98 (s, 1H), 6.95-7.00 (m, 1H), 7.25-7.27 (m, 1H),7.50-7.54 (m, 1H), 7.84-7.88 (m, 1H), 7.91-7.93 (m, 1H), 7.93-7.97 (m,1H)

A flask equipped with a stirrer and a thermometer was charged with 3.16g of the intermediate IMDBT-12 prepared above, 3.91 g of potassiumcarbonate, 5.60 g of 1-iodopentane, and 16.8 g of methylethylketone in anitrogen atmosphere, and heated to 80 to 85° C. The mixture was stirredat the same temperature for 4 hours, and cooled to room temperature.Inorganic salt was filtered out, and the filtrate was washed with 100 mlof ethyl acetate. The filtrate and the used washing liquid were vacuumconcentrated. The concentrate was purified by silica gel chromatographyusing hexane as an eluting solvent to obtain 3.31 g of IMDBT-13. The¹H-NMR spectrum data of the resulting IMDBT-13 are shown below.

¹H-NMR (CDCl₃, δ): 0.95 (t, 3H, J=6 Hz), 1.39-1.51 (m, 4H), 1.84 (tt,2H, J=6 Hz, 6 Hz), 4.05 (t, 2H, J=6 Hz), 7.03-7.06 (m, 1H), 7.26-7.29(m, 2H), 7.50-7.53 (m, 1H), 7.85-7.98 (m, 3H)

A flask equipped with a stirrer and a thermometer was charged with 3.30g of IMDBT-13 prepared above, 0.03 g ofdichlorobis(triphenylphosphine)palladium, 0.06 g of triphenylphosphine,0.03 g of copper iodide, and 18.9 ml of triethylamine in a nitrogenatmosphere, and heated to 60° C. 3.30 g of IM-2 dissolved in 2 g oftriethylamine was added dropwise at 60 to 65° C. over 1 hour, stirred at70° C. for 7 hours, and cooled to room temperature. The inorganic saltswere filtered out, and the filtrate was washed with 100 ml ofethylacetate and vacuum concentrated. The concentrate was mixed with 20ml of methanol and 0.10 g of p-toluenesulfonic acid, stirred at roomtemperature for 4 hours, and neutralized with 1.3 ml of triethylamine toterminate the reaction. The reaction liquid was concentrated, and theconcentrate was purified by silica gel chromatography using 10:1hexane/ethyl acetate mixed with 0.1 wt % triethylamine as an elutingsolvent, to thereby obtain 4.30 g of IMDBT-14.

A flask equipped with a stirrer and a thermometer was charged with 3.92g of the intermediate IMDBT-14 prepared above, 0.4 g of4-pyrrolidinopyridine, 15.1 ml of pyridine, and 37.8 ml ofdichloromethane in a nitrogen atmosphere, and ice cooled. Then 3.5 g oftrifluoromethanesulfonic acid anhydride dissolved in 10 ml ofdichloromethane was added dropwise at 1 to 3° C. over 1 hour, andstirred at the same temperature for 4 hours. After the termination ofthe reaction, 200 ml of ethyl acetate and 50 ml of water were added forextraction, and the resulting organic phase was separated, washed withwater, and vacuum concentrated. The concentrate was purified by silicagel chromatography using 10:1 hexane/ethyl acetate mixed with 0.1 wt %triethylamine as an eluting solvent to obtain 4.10 g of IMDBT-15. The¹H-NMR spectrum data of the resulting IMDBT-15 as well as the reactionformulae of the series of reactions above are shown below.

¹H-NMR (CDCl₃, δ): 0.95 (t, 3H, J=6 Hz), 1.30 (t, 3H, J=6 Hz), 1.40-1.54(m, 4H), 1.85 (tt, 2H, J=6 Hz, 6 Hz), 2.76 (q, 2H, J=6 Hz), 4.06 (t, 2H,J=6 Hz), 7.05-7.08 (m, 1H), 7.23-7.32 (m, 2H), 7.43-7.58 (m, 3H),7.97-8.02 (m, 3H)

Production Example 2-4

A flask equipped with a stirrer and a thermometer was charged with 5.2 gof the intermediate IMDBT-12 prepared in Production Example 2-3, 0.007 gof p-toluenesulfonic acid, and 150 ml of chloroform in a nitrogenatmosphere, and ice cooled. Then 4.8 g of dihydropyran was addeddropwise at 1° C., stirred at the same temperature for 6 hours, andneutralized with 3 ml of triethylamine to terminate the reaction. Thereaction liquid was concentrated, and the concentrate was purified bysilica gel chromatography using 13:1 hexane/ethyl acetate mixed with 0.1wt % triethylamine as an eluting solvent, to thereby obtain 6.42 g ofIMDBT-16.

A flask equipped with a stirrer and a thermometer was charged with 3.5ml of 1-hexyne and 5 ml of tetrahydrofuran in a nitrogen atmosphere, andfurther 36 ml of 1M catecholborane/tetrahydrofuran solution was added.The mixture was heated to 68° C., and stirred at the same temperaturefor 8 hours. After the termination of the reaction, the reaction masswas concentrated in a nitrogen atmosphere, and passed to the next stepas it was without isolating IMDBT-17 generated therein.

A flask equipped with a stirrer and a thermometer was charged with theconcentrate containing IMDBT-17, 5.0 g of the intermediate IMDBT-16, 1.6g of tetrakis(triphenylphosphine)palladium, 26 ml of toluene, and 40 mlof ethanol in a nitrogen atmosphere, and 11 ml of 2M sodium carbonateaqueous solution was added dropwise at room temperature over 20 minutes.The mixture was heated to 73° C., refluxed at the same temperature for 4hours, stirred, cooled to room temperature, and mixed with ethyl acetateand water for extraction. The resulting organic phase was washed fourtimes with water, vacuum concentrated, and the concentrate was passed tothe next step as it was without isolating IMDBT-18 generated therein.

A flask equipped with a stirrer and a thermometer was charged with theconcentrate containing IMDBT-18, 41 ml of methanol, and 0.5 g ofp-toluenesulfonic acid in a nitrogen atmosphere, and stirred at roomtemperature for 3 hours. Then the reaction mixture was neutralized with2 ml of triethylamine to terminate the reaction, concentrated, andpurified by silica gel chromatography using 8:1 hexane/ethyl acetatemixed with 0.1 wt % triethylamine as an eluting solvent, to therebyobtain 3.5 g of IMDBT-19.

A flask equipped with a stirrer and a thermometer was charged with 3.8 gof the intermediate IMDBT-19, 0.6 g of 4-pyrrolidinopyridine, 22 ml ofpyridine, and 54 ml of dichloromethane in a nitrogen atmosphere, and icecooled. Then 2.6 ml of trifluoromethanesulfonic acid anhydride dissolvedin 8 ml of dichloromethane was added dropwise at 1 to 3° C. over 1 hour,and stirred at the same temperature for 4 hours. After the terminationof the reaction, 80 ml of dichloromethane and 50 ml of water were addedfor extraction, and the resulting organic phase was separated, washedwith water, and vacuum concentrated. The concentrate was purified bysilica gel chromatography using 5:1 hexane/ethyl acetate mixed with 0.1wt % triethylamine as an eluting solvent, to obtain 4.4 g of IMDBT-20.The ¹H-NMR spectrum data of the resulting IMDBT-20 are shown below.

¹H-NMR (CDCl₃, δ): 0.95 (t, 3H, J=6 Hz), 1.36-1.52 (m, 4H, J=6 Hz), 2.29(dt, 2H, Jd=6 Hz, Jt=6 Hz), 6.35 (dt, 1H, Jd=15 Hz, Jt=6 Hz), 6.50 (d,1H, J=15 Hz), 7.31-7.35 (m, 1H), 7.47-7.50 (m, 1H), 7.72-7.78 (m, 2H),8.00-8.11 (m, 2H)

A flask equipped with a stirrer and a thermometer was charged with 3.0 gof the intermediate IMDBT-20, 0.2 g ofdichlorobis(triphenylphosphine)palladium, 1.5 ml of triethylamine, and29 ml of dimethylformamide in a nitrogen atmosphere, and heated to 45°C. Then 2 ml of trimethylsilylacetylene was added dropwise, and stirredat the same temperature for 4 hours. The mixture was cooled to roomtemperature, and mixed with 50 ml of diethyl ether and 20 ml of waterfor extraction. The resulting organic phase was separated, washed withwater, and vacuum concentrated. The concentrate was subjected to silicagel chromatography using 20:1 hexane/ethyl acetate mixed with 0.1 wt %triethylamine as an eluting solvent, to obtain 2.60 g of IMDBT-21.

A flask equipped with a stirrer and a thermometer was charged with 2.60g of the intermediate IMDBT-21, 0.3 g of potassium carbonate, 70 ml ofmethanol, and 35 ml of tetrahydrofuran in a nitrogen atmosphere, andstirred at room temperature for 2 hours. Then ethyl acetate was added,the inorganic substances were filtered out, and the filtrate was washedwith ethyl acetate. The filtrate and the used washing liquid were vacuumconcentrated, and purified by silica gel chromatography using 20:1hexane/ethyl acetate mixed with 0.1 wt % triethylamine as an elutingsolvent to obtain 1.57 g of the objective IMDBT-22. The ¹H-NMR spectrumdata of the resulting IMDBT-22, as well as the reaction formulae of theseries of reactions above are shown below.

¹H-NMR (CDCl₃, δ): 0.94 (t, 3H, J=6 Hz), 1.35-1.53 (m, 4H), 2.26 (dt,2H, Jd=6 Hz, Jt=6 Hz), 3.17 (s, 1H), 6.34 (dt, 1H, Jd=15 Hz, Jt=6 Hz),6.49 (d, 1H, J=15 Hz), 7.43-7.46 (m, 1H), 7.51-7.55 (m, 1H), 7.76-7.77(m, 1H), 7.94-8.11 (m, 3H)

Example 2-3

A flask equipped with a stirrer and a thermometer was charged with 1.90g of IMDBT-15 prepared in Production Example 2-3, 0.07 g ofdichlorobis(triphenylphosphine) palladium, 0.7 ml of triethylamine, and14 ml of dimethylformamide in a nitrogen atmosphere, and heated to 60°C. Then 1.60 g of IMDBT-22 prepared in Production Example 2-4 dissolvedin 4 ml of dimethylformamide was added dropwise at the same temperatureover 8 hours, and stirred at 60° C. for 2 hours. After the terminationof the reaction, 20 ml of diethyl ether and 10 ml of water were addedfor extraction, and the resulting organic phase was washed twice with 10ml of water, and concentrated. The concentrate was purified by silicagel chromatography using 10:1 hexane/chloroform mixed with 0.1 wt %triethylamine as an eluting solvent, to obtain 120 mg of the objectivecompound DBT1125. The ¹H-NMR spectrum data of the resulting DBT1125, aswell as the reaction formulae of the reaction above are shown below.

¹H-NMR (CDCl₃, δ): 0.95 (t, 3H, J=6 Hz), 0.96 (t, 3H, J=6 Hz), 1.34-1.48(m, 11H), 1.85 (tt, 2H, J=6 Hz, 6 Hz), 2.26 (dt, 2H, Jd=6 Hz, Jt=6 Hz),2.93 (q, 2H, J=6 Hz), 4.06 (t, 2H, J=6 Hz), 6.34 (dt, 1H, Jd=15 Hz, Jt=6Hz), 6.51 (d, 1H, J=15 Hz), 7.05-7.09 (m, 1H), 7.31-7.61 (m, 7H),7.79-7.80 (m, 1H), 7.98-8.09 (m, 6H)

The phase sequence of the compound DBT1125 was evaluated in the samemanner as in Example 2-1, to find that the compound was in thecrystalline phase below 226° C., and in the liquid crystalline phasefrom 226° C. When the compound was further heated to 300° C., no phasetransition was observed. It was thus demonstrated that this compound wasa liquid crystalline compound.

5 wt % of the compound DBT1125 was added to a nematic compositionMJ931381 (manufactured by Merck Japan Co.) and the refractive indexanisotropy Δn was determined, from which Δn of the compound wasextrapolated based on the concentration. It was determined that the Δnof the compound was 0.63, which is an extremely large value. Δn wasmeasured with an Abbe refractometer at 20° C. and at the wavelength of589 nm.

The obtained DBT1125 was theoretically divided into the following parts,and the difference ΔE in energy of HOMO of the parts and thepolarizability anisotropy Δα were calculated by the method of molecularorbitals. The results are as follows:

Example 2-4

Liquid crystal composition M-1 was prepared by mixing 6.9 wt % ofDBT1115 prepared in Example 2-1, 2.6 wt % of DBT1116 prepared in Example2-2, 30 wt %, 21.4 wt %, and 7.1 wt % of the compounds represented bythe formulae (5-1), (5-2), and (5-3), respectively, as compoundsrepresented by the formula (5), 8.2 wt % and 5.8 wt % of the compoundsrepresented by the formulae (6-1) and (6-2), respectively, as compoundsrepresented by the formula (6), and 13.7 wt % and 4.3 wt % of thecompounds represented by the formulae (7-1) and (7-2), respectively, asa compound represented by the formula (7).

The phase sequence of the composition M-1 was evaluated in the samemanner as in Example 2-1 to find that the composition was in the nematicphase in the temperature range of 7 to 195° C. The refractive indexanisotropy of the composition M-1 was measured, using a glass cell withthe tip angle of 1.6 degree pretreated for parallel alignment and filledwith M-1, in accordance with the Hollow Prism Method described inHandbook of Liquid Crystals, Vol. 2A, p 129 (ed. by D. Demus et al.,Wiley-VCH Verlag GmbH), using helium-neon laser as a light source. Itwas found that the refractive index anisotropy of the composition M-1was 0.43 (20° C., 632.8 nm), which is an extremely large value.

Example 2-5

Liquid crystal composition M-2 was prepared by mixing 2.2 wt % ofDBT1115 prepared in Example 2-1, 5.9 wt % of DBT1116 prepared in Example2-2, 20.2 wt %, 6.5 wt %, 21.9 wt %, and 13.5 wt % of the compoundsrepresented by the formulae (5-1), (5-3), (5-4), and (5-5),respectively, as compounds represented by the formula (5), 8.3 wt % and6.0 wt % of the compounds represented by the formulae (6-1) and (6-2),respectively, as compounds represented by the formula (6), and 12.0 wt %and 3.6 wt % of the compounds represented by the formulae (7-1) and(7-2), respectively, as compounds represented by the formula (7).

The phase sequence of the composition M-2 was evaluated to find that thecomposition was in the nematic phase at room temperature, and underwenttransition from a nematic to isotropic phase at 175° C. The refractiveindex anisotropy of the composition M-2 was measured in the same manneras in Example 2-4, to find that the refractive index anisotropy of M-2was 0.46 at 632.8 nm and 0.51 at 543.5 nm, which are extremely largevalues.

Production Example 3-1

A flask equipped with a stirrer and a thermometer was charged with 44.1g of a starting material IMDBT-4 and 441 g of carbon tetrachloride in anitrogen atmosphere, and cooled to −5° C. The mixture was then bubbledwith a chlorine gas under stirring at −7° C. to −12° C. for 5 hours. Thereaction mass was poured into 1000 g of ice water, and stirred at orbelow 5° C. for 40 minutes. The reactant was separated by filtration,washed with carbon tetrachloride, and the resulting crystals were driedto obtain 27.91 g of IMDBT-9.

A flask equipped with a stirrer and a thermometer was charged with 69.8g of glacial acetic acid and 27.9 g of IMDBT-9 prepared above in anitrogen atmosphere, and cooled to 10° C. Then 239.8 g of concentratedsulfuric acid was added dropwise, and cooled to −2° C. 72.0 g of 70 wt %nitric acid was then added dropwise at −2 to 8° C., and stirred at orbelow 5° C. for 2 hours. The reaction mass was poured into 1200 g of icewater to terminate the reaction, and stirred further. The reactant wasseparated by filtration, washed with water, and dried. The resulting drycake was washed with ethanol to obtain 31.9 g of IMDBT-10.

A flask equipped with a stirrer and a thermometer was charged with 26.98g of IMDBT-10 and 269.8 g of glacial acetic acid in a nitrogenatmosphere. 112.7 g of SnCl₂.2H₂O dissolved in 158 g of concentratedhydrochloric acid was added dropwise at 14 to 18° C. over 1 hour, andstirred overnight at room temperature. The reactant was filtered, washedwith 1:1 glacial acetic acid/concentrated hydrochloric acid, andneutralized with 1100 g of a 7 wt % aqueous solution of sodiumhydroxide. The reactant was extracted with ethyl acetate, washed withwater, concentrated, and purified by silica gel chromatography using 1:1hexane/chloroform mixed with 0.1 wt % triethylamine as an elutingsolvent, to thereby obtain 17.31 g of IMDBT-11.

A flask equipped with a stirrer and a thermometer was charged with 209.3g of concentrated sulfuric acid and 8.93 g of NaNO₂ in a nitrogenatmosphere, and cooled to 2° C. Then 24.0 g of IMDBT-11 prepared abovewas added, and stirred at 2 to 4° C. for 3 hours. The resulting mixturetogether with 99.8 g of water was poured into 348.7 g of 65 wt %sulfuric acid preheated to 80° C., stirred at 80 to 85° C. for 5 hours,and cooled to room temperature. The reactant was filtered, extracted sixtimes with 300 ml of ethyl acetate, and vacuum concentrated. Theconcentrate was purified by silica gel chromatography using chloroformas an eluting solvent to obtain 7.11 g of IMDBT-12. The ¹H-NMR spectrumdata of the resulting IMDBT-12 are shown below.

¹H-NMR (CDCl₃, δ): 4.98 (s, 1H), 6.95-7.00 (m, 1H), 7.25-7.27 (m, 1H),7.50-7.54 (m, 1H), 7.84-7.88 (m, 1H), 7.91-7.93 (m, 1H), 7.93-7.97 (m,1H)

A flask equipped with a stirrer and a thermometer was charged with 1.34g of IMDBT-12, 1.66 g of potassium carbonate, 2.51 g of 8-bromo-octanol,and 13.4 g of methylethylketone in a nitrogen atmosphere, heated to 80to 85° C., stirred at the same temperature for 5 hours, and cooled toroom temperature. The solvent was evaporated under reduced pressure, andthe residue was purified by silica gel chromatography using 10:1hexane/ethyl acetate as an eluting solvent, to thereby obtain 1.57 g ofIMDBT-23.

A flask equipped with a stirrer and a thermometer was charged with 2.85g of IMDBT-23, 1.21 g of triethylamine, and 28.5 g of tetrahydrofuran ina nitrogen atmosphere, and cooled to 0 to 5° C. 0.94 g of acetylchloride dissolved in 2.0 g of tetrahydrofuran was added dropwise at thesame temperature, and stirred for 30 minutes. After the termination ofthe reaction, 100 ml of ethyl acetate and 50 ml of water were added forextraction, and the resulting organic phase was separated, washed withwater, and vacuum concentrated. The concentrate was purified by silicagel chromatography using 20:1 hexane/ethyl acetate as an elutingsolvent, to obtain 2.07 g of IMDBT-24.

A flask equipped with a stirrer and a thermometer was charged with 1.63g of IMDBT-24, 0.08 g of dichlorobis(triphenylphosphine)palladium, 0.04g of triphenylphosphine, 0.04 g of copper iodide, 3.67 g oftriethylamine, and 16.3 g of dimethylformamide in a nitrogen atmosphere,and heated to 60° C. Then 1.25 g of IM-2 dissolved in 1.2 g ofdimethylformamide was added dropwise, stirred at 60 to 65° C. for 14hours, and cooled to room temperature. 100 ml of ethyl acetate and 100ml of water were added for extraction, and the resulting organic phasewas separated, washed with water, and vacuum concentrated. Theconcentrate was mixed with 16.7 g of tetrahydrofuran, 16.7 g ofmethanol, and 0.10 g of p-toluenesulfonic acid, stirred at roomtemperature for 3 hours, and neutralized with 2 ml of triethylamine toterminate the reaction. The reaction liquid was concentrated, and mixedwith 200 ml of ethyl acetate and 100 ml of water for extraction. Theresulting organic phase was separated, washed with water, and vacuumconcentrated. The concentrate was purified by silica gel chromatographyusing 5:1 hexane/ethyl acetate mixed with 0.1 wt % triethylamine as aneluting solvent, to thereby obtain 0.94 g of IMDBT-25.

A flask equipped with a stirrer and a thermometer was charged with 2.06g of IMDBT-25, 0.04 g of 4-pyrrolidinopyridine, 4.12 g of pyridine, and20.6 g of toluene in a nitrogen atmosphere, and cooled to −2° C. Then2.26 g of trifluoromethanesulfonic acid anhydride dissolved in 4.5 g oftoluene was added dropwise at −2 to 0° C., heated to room temperature,and stirred overnight. 100 ml of ethyl acetate and 50 ml of water wereadded for extraction, and the resulting organic phase was separated,washed with water, and vacuum concentrated. The concentrate was purifiedby silica gel chromatography using 1:1 hexane/chloroform as an elutingsolvent to obtain 2.51 g of IMDBT-26. The reaction formulae of theseries of reactions above are as follows:

Production Example 3-2

A flask equipped with a stirrer and a thermometer was charged with 2.55g of IMDBT-12 prepared in Production Example 3-1, 3.16 g of potassiumcarbonate, 4.14 g of 6-bromohexanol, and 12.8 g of methylethylketone ina nitrogen atmosphere, and heated to 80 to 85° C. The mixture wasstirred at the same temperature for 3 hours, cooled to room temperature,and the solvent was evaporated under reduced pressure. The residue waspurified by silica gel chromatography using 5:1 hexane/ethyl acetate asan eluting solvent, and recrystallized from ethyl acetate solvent, tothereby obtain 2.20 g of IMDBT-27.

A flask equipped with a stirrer and a thermometer was charged with 2.20g of IMDBT-27, 0.01 g of p-toluenesulfonic acid, and 66.0 g ofchloroform in a nitrogen atmosphere, and cooled to 0 to 5° C. 1.96 g ofdihydropyran dissolved in 6.0 g of chloroform was added dropwise at thesame temperature, stirred at the same temperature for 1 hour, andneutralized with 0.5 ml of triethylamine to terminate the reaction. Thesolvent was evaporated under reduced pressure, and the residue waspurified by silica gel chromatography using chloroform mixed with 0.1 wt% triethylamine as an eluting solvent, to thereby obtain 2.53 g ofIMDBT-28.

A flask equipped with a stirrer and a thermometer was charged with 3.56g of IMDBT-28, 0.18 g of dichlorobis(triphenylphosphine)palladium, 0.18g of triphenylphosphine, 0.09 g of copper iodide, 7.77 g oftriethylamine, and 35.6 g of dimethylformamide in a nitrogen atmosphere,and heated to 60° C. 1.54 g of trimethylsilylacetylene dissolved in 3.1g of dimethylformamide was added dropwise, stirred at 60 to 65° C. for 3hours, and cooled to room temperature. 100 ml of ethyl acetate and 50 mlof water were added for extraction, and the resulting organic phase wasseparated, washed with water, and vacuum concentrated. 4.37 g of theconcentrate was mixed with 26.2 g of tetrahydrofuran, 26.2 g ofmethanol, and 0.15 g of potassium carbonate, and stirred overnight atroom temperature. The reaction liquid was concentrated, and purified bysilica gel chromatography using 1:1 hexane/chloroform mixed with 0.1 wt% triethylamine as an eluting solvent, to thereby obtain 2.48 g ofIMDBT-29.

A flask equipped with a stirrer and a thermometer was charged with 1.32g of IMDBT-26 prepared in Production Example 3-1, 0.03 g ofdichlorobis(triphenylphosphine) palladium, 0.31 g of triethylamine, and13.2 g of dimethylformamide in a nitrogen atmosphere, and heated to 60°C. Then 1.32 g of IMDBT-29 dissolved in 4.0 g of dimethylformamide wasadded dropwise, and stirred at 60 to 65° C. for 10 hours. 100 ml ofethyl acetate and 50 ml of water were added at 50 to 55° C. forextraction, and the resulting organic phase was separated, washed withwater, and vacuum concentrated. The concentrate was subjected to silicagel chromatography using 2:3 hexane/chloroform mixed with 0.1 wt %triethylamine as an eluting solvent, and then purified by silica gelchromatography using 2:1 hexane/chloroform mixed with 0.1 wt %triethylamine as an eluting solvent, to thereby obtain 1.10 g ofIMDBT-30.

A flask equipped with a stirrer and a thermometer was charged with 2.20g of IMDBT-30, 0.16 g of p-toluenesulfonic acid, 66.0 g oftetrahydrofuran, 63.0 g of methanol, and 240 g of chloroform in anitrogen atmosphere, and stirred at room temperature overnight. Themixture was neutralized with 2.0 g of triethylamine to terminate thereaction, vacuum concentrated, subjected to silica gel chromatographyusing chloroform mixed with 0.1 wt % triethylamine as an elutingsolvent, and vacuum concentrated. 1.70 g of the concentrate wasintroduced into a flask equipped with a stirrer and a thermometer in anitrogen atmosphere, and dissolved in 204 g of tetrahydrofuran. Then0.17 g of LiAlH₄ was added at room temperature, stirred at roomtemperature for 3 hours, mixed with 20 g of 5 wt % sodium hydroxide toterminate the reaction, and vacuum concentrated. The concentrate waspurified by silica gel chromatography using 5:1 chloroform/ethyl acetatemixed with 0.1 wt % triethylamine to obtain 1.10 g of IMDBT-31. Thereaction formulae of the series of reactions above are as follows:

Example 3-1

A flask equipped with a stirrer and a thermometer was charged with 0.50g of IMDBT-31 prepared in Production Example 3-2, 20 g of1-methyl-2-pyrolidone, and 0.65 g of triethylamine in a nitrogenatmosphere, and stirred at room temperature. Then 0.34 g of acrylic acidchloride dissolved in 10 g of chloroform was added dropwise, and stirredat room temperature for 4 hours. When the starting materials wereconfirmed by TLC to have been disappeared, 100 ml of ethyl acetate and100 ml of water were added for extraction. The organic phase wasconcentrated, and the resulting solid was purified by silica gelchromatography using 2:1 hexane/chloroform mixed with 0.1 wt %triethylamine as an eluting solvent, to thereby obtain 0.39 g of theobjective compound DBT1124. The ¹H-NMR spectrum data of the resultingDBT1124, as well as the formulae of the reaction above are shown below.

¹H-NMR (CDCl₃, δ): 1.17-1.82 (m, 23H), 2.86 (q, 2H, J=7.5 Hz), 3.96 (t,2H, J=6.5 Hz), 3.97 (t, 2H, J=6.4 Hz), 4.08 (t, 2H, J=6.8 Hz), 4.10 (t,2H, J=6.7 Hz), 5.73 (d, 2H, J=9.4 Hz), 6.05 (dd, 2H, J=17.2 Hz, 9.4 Hz),6.33 (d, 2H, J=17.2 Hz), 6.94-6.98 (m, 2H), 7.28-7.62 (m, 7H), 7.87-7.93(m, 6H)

The obtained DBT1124 was theoretically divided into the following parts,and the difference ΔE in energy of HOMO of the parts and thepolarizability anisotropy Δα were calculated by the method of molecularorbitals. The results are as follows:

The phase sequence of the compound DBT1124 was evaluated withpolarization microscope to find that the compound was in the crystallinephase below 124° C., in the nematic phase from 124° C. to at least 300°C., and in the isotropic phase above 253° C. It was thus demonstratedthat this compound is a crystalline compound.

10 wt % of the compound DBT1124 was added to a nematic compositionMJ931381 (manufactured by Merck Japan Co.) and the refractive indexanisotropy Δn was determined, from which Δn of the compound wasextrapolated based on the concentration. It was determined that the Δnof the compound was 0.41, which is an extremely large value. Δn wasmeasured with an Abbe refractometer at 20° C. and at the wavelength of589 nm.

Example 3-2

DBT1124 prepared in Example 3-1 was mixed with 3 wt % of aphotopolymerization initiator (trade name “IRGACURE 651” manufactured byCIBA GEIGY AG), and the resulting mixture was injected into atransparent glass cell having a cell gap of about 8 μm. The transparentglass cell had been fabricated by forming polyimide thin films on thesurfaces of two glass substrates, rubbing the surfaces, and arrangingthe two substrates with the directions of rubbing being parallel to eachother. The glass cell was irradiated with a light from a high-pressuremercury lamp at 1600 mJ/cm² at 125° C. to polymerize the liquidcrystalline monomer in the cell. Through polarization microscopicobservation of the cell, it was confirmed that an optically anisotropicproduct had been obtained wherein the nematic alignment had beenuniformly fixed.

Next, the same liquid crystalline material containing thephotopolymerization initiator was injected into a cell composed of twoglass substrates that had been treated for alignment in the same manneras above and arranged in the form of a wedge of about 1.6 degree, andpolymerized under the same conditions as above. The cell thus fabricatedwas measured for the refractive index anisotropy using helium-neon laserin accordance with the method described in Handbook of Liquid Crystals,Vol. 2A, p 129 (ed. by D. Demus, J. Goodby, G. W. Dray, H. W. Spiess,and V. Vill, WILEY-VCH-Verlag). It was found that the refractive indexanisotropy was 0.35 at 20° C., which is an extremely large value.

Example 3-3

Liquid crystal composition M-3 was prepared by mixing 65.7 wt % ofDBT1124 prepared in Example 3-1 and 34.3 wt % of the compoundrepresented by the formula (4-1) as a compound represented by theformula (4). The obtained liquid crystal composition M-3 was mixed with3 wt % of a photopolymerization initiator (trade name “IRGACURE 651”manufactured by CIBA GEIGY AG), and the resulting mixture was injectedinto a transparent glass cell in the same manner as in Example 3-2, andpolymerized. Through polarization microscopic observation of the cell,it was confirmed that an optically anisotropic product had been obtainedwherein the nematic alignment had been uniformly fixed.

Further, the refractive index anisotropy of the same liquid crystallinematerial was measured in the same manner as in Example 3-2. It was foundthat the refractive index anisotropy was 0.384 (632.8 nm) at 20° C.,which is an extremely large value.

Although the present invention has been described with reference to thepreferred examples, it should be understood that various modificationsand variations can be easily made by those skilled in the art withoutdeparting from the spirit of the invention. Accordingly, the foregoingdisclosure should be interpreted as illustrative only and is not to beinterpreted in a limiting sense. The present invention is limited onlyby the scope of the following claims.

1. A dibenzothiophene compound represented by the formula (A-1):

wherein A¹ to A⁶ each independently stands for a hydrogen atom, afluorine atom, an alkyl or alkoxy group having 1 to 10 carbon atomsoptionally substituted with at least one fluorine atom, X stands for ahalogen atom, and Y stands for a halogen atom or a hydroxyl group.
 2. Adibenzothiophene compound represented by the formula (A-2):

wherein A¹ to A⁶ each independently stands for a hydrogen atom, afluorine atom, an alkyl or alkoxy group having 1 to 10 carbon atomsoptionally substituted with at least one fluorine atom, and X stands fora halogen atom.
 3. A method for producing the dibenzothiophene compoundof claim 1 comprising: diazotizing a dibenzothiophene compoundrepresented by the formula (A-2) to obtain a diazonium salt,

wherein A¹ to A⁶ each independently stands for a hydrogen atom, afluorine atom, an alkyl or alkoxy group having 1 to 10 carbon atomsoptionally substituted with at least one fluorine atom, and X stands fora halogen atom, and decomposing said diazonium salt in the presence ofan anion corresponding to Y in the formula (A-1):

wherein A¹ to A⁶ and X mean the same as those in the formula (A-2), andY stands for a halogen atom or a hydroxyl group.
 4. A method forproducing the dibenzothiophene compound of claim 2 comprising reducing adibenzothiophene oxide compound represented by the formula (A-3):

wherein A¹ to A⁶ each independently stands for a hydrogen atom, afluorine atom, an alkyl or alkoxy group having 1 to 10 carbon atomsoptionally substituted with at least one fluorine atom, and X stands fora halogen atom.